Condition

Muscle Size & Strength

Muscle grows when resistance training stresses the fibers and the body rebuilds them larger, using protein and rest. Creatine and protein have the strongest evidence: trials found creatine improved short, intense exercise capacity, and protein supplements, including soy, beef and casein, improved muscle mass, with gains similar to whey. Many of those studies were small, and supplements work alongside training rather than replacing it.

Sources: PMID 14625517; PMID 39813010

Supplements studied: 45
Graded outcomes: 43
Trials: 153
People studied: 25,809

Evidence by supplement

Strong
Moderate
Limited
Very limited

45 supplements

Creatine

Creatine: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Anaerobic Capacity Small Improvement	Improves (the measure goes up)	Small effect	11 studies	90 people
Studies that measured anaerobic capacity Short-term creatine supplementation does not improve muscle activation or sprint performance in humansEur J Appl Physiol · PMID 14574579 Creatine supplementation: effects on urinary excretion and anaerobic performanceJ Sports Med Phys Fitness · PMID 14625517 Creatine supplementation and performance in 6 consecutive 60 meter sprintsJ Physiol Biochem · PMID 15957245 and 8 more on the Creatine page
	Aerobic Exercise Metrics No effect		NoneNo effect	2 studies	18 people
Studies that measured aerobic exercise metrics Creatine supplementation does not enhance submaximal aerobic training adaptations in healthy young men and womenEur J Appl Physiol · PMID 16896727 A randomized, controlled trial of creatine monohydrate in patients with mitochondrial cytopathiesMuscle Nerve · PMID 9390662
	Power Output	Improves (the measure goes up)		44 studies	469 people
Studies that measured power output Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flowMetabolism · PMID 11735088 Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performanceInt J Sport Nutr Exerc Metab · PMID 19033611 The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levelsJ Int Soc Sports Nutr · PMID 19228401 and 41 more on the Creatine page
	Muscle Creatine Content	Improves (the measure goes up)		11 studies	164 people
Studies that measured muscle creatine content Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilizationDiabetes · 2001 · PMID 11147785 Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle1999 · PMID 10444618 Effect of creatine monohydrate in improving cellular energetics and muscle strength in ambulatory Duchenne muscular dystrophy patients: a randomized, placebo-controlled 31P MRS studyMagn Reson Imaging · PMID 20395096 and 8 more on the Creatine page
	Weight	Changes; see studies		10 studies	144 people
Studies that measured weight Creatine monohydrate supplementation on body weight and percent body fatJ Strength Cond Res · PMID 14636103 Reliability and detecting change following short-term creatine supplementation: comparison of two-component body composition methodsJ Strength Cond Res · PMID 17530953 Effects of creatine supplementation on aerobic power and cardiovascular structure and functionJ Sci Med Sport · PMID 16248471 and 7 more on the Creatine page
	Hydration (Total Body Water)	Improves (the measure goes up)		5 studies	57 people
	Kidney Function	Improves (the measure goes up)		5 studies	38 people
	Muscle Mass	Improves (the measure goes up)		5 studies	399 people
	Strength	Improves (the measure goes up)		5 studies	142 people
	Muscle Damage	Changes; see studies		4 studies	469 people
	IGF-1	Improves (the measure goes up)		2 studies	98 people
	Muscular Endurance	Improves (the measure goes up)		2 studies	42 people
	Growth Hormone	Improves (the measure goes up)		1 study	6 people
	Satellite Cell Recruitment	Improves (the measure goes up)		1 study	32 people
	Skeletal Muscle Atrophy	Improves (the measure goes up)		1 study	7 people
	Testosterone	Improves (the measure goes up)		1 study	50 people
	Blood Flow	Improves (the measure goes up)			30 people
	Blood Pressure	Changes; see studies			35 people
	Body Fat	Changes; see studies			215 people
	Exercise-Induced Oxidation	Changes; see studies			469 people
	Fatigue Resistance	Changes; see studies			78 people
	Glycogen	Improves (the measure goes up)			12 people
	Inflammation	Changes; see studies			469 people
	Jump Height	Improves (the measure goes up)			1,937 people
	Metabolic Rate	Improves (the measure goes up)			30 people
	Muscle Soreness	Changes; see studies			469 people
	Myonuclei Proliferation	Improves (the measure goes up)			32 people
	Myostatin	Improves (the measure goes up)			27 people
	Peak power output (PPO)	Improves (the measure goes up)			1,937 people
	Proteinuria	Improves (the measure goes up)			38 people
	Range of Motion	Improves (the measure goes up)			40 people

Soy Protein

Soy Protein: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Muscle Mass Small Improvement	Improves (the measure goes up)	Small effect	2 studies	1,048 people
Studies that measured muscle mass No Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance ExerciseInt J Sport Nutr Exerc Metab · PMID 29722584 Effect of Plant Versus Animal Protein on Muscle Mass, Strength, Physical Performance, and Sarcopenia: A Systematic Review and Meta-analysis of Randomized Controlled Trials.Nutr Rev · PMID 39813010
	Strength	Improves (the measure goes up)			266 people

Ashwagandha

Aerobic Exercise Metrics: improves
Testosterone: improves
Oxygen Uptake: improves

Ashwagandha: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Aerobic Exercise Metrics Moderate Improvement	Improves (the measure goes up)	Moderate effect	1 study	226 people
Studies that measured aerobic exercise metrics Effects of Ashwagandha ( Withania somnifera) on Physical Performance: Systematic Review and Bayesian Meta-AnalysisJ Funct Morphol Kinesiol · PMID 33670194
	Testosterone	Improves (the measure goes up)		5 studies	57 people
Studies that measured testosterone Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trialJ Int Soc Sports Nutr · PMID 26609282 Efficacy of Withania somnifera on seminal plasma metabolites of infertile males: a proton NMR study at 800 MHzJ Ethnopharmacol · PMID 23796876 Withania somnifera Improves Semen Quality in Stress-Related Male FertilityEvid Based Complement Alternat Med · PMID 19789214 and 2 more on the Ashwagandha page
	Oxygen Uptake	Improves (the measure goes up)		2 studies	40 people
Studies that measured oxygen uptake Effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adultsInt J Ayurveda Res · PMID 21170205 Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclistsJ Ayurveda Integr Med · PMID 23326093
	High-density lipoprotein (HDL)	Improves (the measure goes up)		1 study	57 people
Studies that measured high-density lipoprotein (hdl) Effects of Withania somnifera in patients of schizophrenia: A randomized, double blind, placebo controlled pilot trial studyIndian J Pharmacol · PMID 24014929
	Red Blood Cell Count	Improves (the measure goes up)		1 study	57 people
Studies that measured red blood cell count Effects of an Aqueous Extract of Withania somnifera on Strength Training Adaptations and Recovery: The STAR TrialNutrients · PMID 30463324
	White Blood Cell Count	Improves (the measure goes up)		1 study	57 people
	Anaerobic Capacity	Improves (the measure goes up)			40 people
	Blood Pressure	Changes; see studies			40 people
	Body Fat	Changes; see studies			114 people
	Exercise Capacity	Improves (the measure goes up)			40 people
	Hematocrit	Improves (the measure goes up)			40 people
	Hemoglobin	Improves (the measure goes up)			40 people
	Kidney Function	Improves (the measure goes up)			40 people
	Liver Enzymes	Changes; see studies			57 people
	Low-density lipoprotein (LDL)	Changes; see studies			57 people
	Muscle Damage	Changes; see studies			57 people
	Muscle Mass	Improves (the measure goes up)			57 people
	Muscle Soreness	Changes; see studies			40 people
	Power Output	Improves (the measure goes up)			154 people
	Rating of Perceived Exertion	Improves (the measure goes up)			17 people
	Serum Albumin	Improves (the measure goes up)			40 people
	Serum Platelets	Improves (the measure goes up)			17 people
	Strength	Improves (the measure goes up)			198 people
	Subjective Well-Being	Improves (the measure goes up)			40 people
	Total cholesterol	Changes; see studies			57 people
	Triglycerides	Changes; see studies			57 people
	Urea	Improves (the measure goes up)			40 people
	vLDL-C	Changes; see studies			40 people
	Weight	Changes; see studies			57 people

Calcium Caseinate

Muscle Protein Synthesis: improves

Calcium Caseinate: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Muscle Protein Synthesis Casein stimulates MPS comparably to whey over 24h despite lower acute peak. With resistance training, muscle gains are similar to whey protein.	Improves (the measure goes up)	Moderate effect		200 people

Beef Protein

Lean Mass Gains: improves
Lower-Limb Strength: improves

Beef Protein: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Lean Mass Gains Meta-analysis (PMID: 31261854): no difference from whey (SMD -0.01, p=0.970); BP vs no protein: SMD 0.34, p=0.049	Improves (the measure goes up)	Moderate effect		270 people
	Lower-Limb Strength Meta-analysis: BP vs no protein significantly increased lower-limb strength (SMD 0.40, p=0.014)	Improves (the measure goes up)	Moderate effect		270 people

Chromium

Body Fat: improves
Weight: changes; see studies
Muscle Mass: improves

Chromium: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Body Fat Small Decrease	Improves (the measure goes down)	Small effect		103 people
	Weight	Changes; see studies		12 studies	103 people
Studies that measured weight Chromium picolinate supplementation in women: effects on body weight, composition, and iron statusNutrition · PMID 17291720 Effect of resistance training with or without chromium picolinate supplementation on glucose metabolism in older men and womenMetabolism · PMID 10337851 Chromium supplementation shortens QTc interval duration in patients with type 2 diabetes mellitusAm Heart J · PMID 15990745 and 9 more on the Chromium page
	Muscle Mass	Improves (the measure goes up)		5 studies	103 people
Studies that measured muscle mass Effects of resistance training and chromium picolinate on body composition and skeletal muscle in older menJ Appl Physiol · 1985 · PMID 9887110 Effects of resistive training and chromium picolinate on body composition and skeletal muscle size in older womenInt J Sport Nutr Exerc Metab · PMID 12187613 The effect of chromium picolinate on muscular strength and body composition in women athletesJ Strength Cond Res · PMID 11710399 and 2 more on the Chromium page
	Insulin	Changes; see studies		1 study	35 people
Studies that measured insulin A pilot study of chromium picolinate for weight lossJ Altern Complement Med · PMID 20192914
	Muscular Endurance	Improves (the measure goes up)			20 people
	Power Output	Improves (the measure goes up)			52 people

Nitrate

Jump Height: improves
Strength: improves
Peak power output (PPO): improves

Nitrate: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Jump Height Small Increase	Improves (the measure goes up)	Small effect		75 people
	Strength	Improves (the measure goes up)		3 studies	73 people
Studies that measured strength Does Nitrate Supplementation Improve Muscle Strength, Power, and Sprint Performance in Females? A Systematic Review and Meta-Analysis.Life · PMID 41010367 Effects of Dietary Nitrate Supplementation on Back Squat and Bench Press Performance: A Systematic Review and Meta-Analysis.Nutrients · PMID 37299456 The Effect of Dietary Nitrate Supplementation on Isokinetic Torque in Adults: A Systematic Review and Meta-Analysis.Nutrients · PMID 33023118
	Peak power output (PPO)	Improves (the measure goes up)		1 study	268 people
Studies that measured peak power output (ppo) Effect of dietary nitrate on human muscle power: a systematic review and individual participant data meta-analysis.J Int Soc Sports Nutr · PMID 34625064
	Power Output	Improves (the measure goes up)		1 study	8 people
Studies that measured power output Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractionsPflugers Arch · PMID 23354414
	Sprint Performance Metrics	Improves (the measure goes up)			67 people

Sodium Bicarbonate

Anaerobic Capacity: improves
Serum Bicarbonate: improves
Power Output: improves

Sodium Bicarbonate: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Anaerobic Capacity Small Improvement	Improves (the measure goes up)	Small effect	11 studies	8 people
Studies that measured anaerobic capacity Sodium bicarbonate improves swimming performanceInt J Sports Med · PMID 18004687 Sodium bicarbonate ingestion and repeated swim sprint performanceJ Strength Cond Res · PMID 20881504 Sodium bicarbonate ingestion improves performance in interval swimmingEur J Appl Physiol Occup Physiol · PMID 2849539 and 8 more on the Sodium Bicarbonate page
	Serum Bicarbonate	Improves (the measure goes up)		26 studies	29 people
Studies that measured serum bicarbonate Effects of various sodium bicarbonate loading protocols on the time-dependent extracellular buffering profileJ Strength Cond Res · PMID 20040895 Acid-base balance during repeated bouts of exercise: influence of HCO3Int J Sports Med · PMID 6094373 Effects of sodium bicarbonate ingestion on prolonged intermittent exerciseMed Sci Sports Exerc · PMID 12900682 and 23 more on the Sodium Bicarbonate page
	Power Output	Improves (the measure goes up)		6 studies	6 people
Studies that measured power output Reliability and effect of sodium bicarbonate: buffering and 2000-m rowing performanceInt J Sports Physiol Perform · PMID 22634964 Influence of sodium bicarbonate on performance and hydration in lightweight rowingInt J Sports Physiol Perform · PMID 21941012 The effect of induced alkalosis and acidosis on plasma lactate and work output in elite oarsmenEur J Appl Physiol Occup Physiol · PMID 2548862 and 3 more on the Sodium Bicarbonate page
	Blood Acidity	Changes; see studies		4 studies	29 people
Studies that measured blood acidity Acidosis stimulates beta-endorphin release during exerciseJ Appl Physiol · PMID 7836218 Time course of blood bicarbonate and pH three hours after sodium bicarbonate ingestionInt J Sports Physiol Perform · PMID 19208932 Effects of sodium bicarbonate on nitrogen metabolism and ketone bodies during very low energy protein diets in obese subjectsMetabolism · PMID 2556622 and 1 more on the Sodium Bicarbonate page
	Blood Lactate (Exercise)	Changes; see studies		2 studies	29 people
Studies that measured blood lactate (exercise) Effects of sodium bicarbonate, caffeine, and their combination on repeated 200-m freestyle performanceInt J Sport Nutr Exerc Metab · PMID 18458356 Repeated bouts of sprint running after induced alkalosisJ Sports Sci · PMID 1664869
	Muscular Endurance	Improves (the measure goes up)		1 study	192 people
	Training Volume	Improves (the measure goes up)		1 study	21 people
	Maximal voluntary isometric contraction (MVIC)	Improves (the measure goes up)			192 people

Caffeine

Blood Lactate (Exercise): worsens
Heart Rate: changes; see studies
Power Output: improves

Caffeine: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Blood Lactate (Exercise) Small Increase	Worsens (the measure goes up)	Small effect	4 studies	13 people
Studies that measured blood lactate (exercise) Effect of Caffeine on LT, VT and HRVTInt J Sports Med · PMID 22499570 Metabolic effects of caffeine ingestion and physical work in 75-year old citizens. A randomized, double-blind, placebo-controlled, cross-over studyClin Endocrinol · PMID 16886964 Caffeine and sprinting performance: dose responses and efficacyJ Strength Cond Res · PMID 22388491 and 1 more on the Caffeine page
	Heart Rate	Changes; see studies		4 studies	25 people
Studies that measured heart rate Dose response effects of a caffeine-containing energy drink on muscle performance: a repeated measures designJ Int Soc Sports Nutr · PMID 22569090 The effects of different doses of caffeine on endurance cycling time trial performanceJ Sports Sci · PMID 22142020 Caffeine supplementation and multiple sprint running performanceMed Sci Sports Exerc · PMID 18799995 and 1 more on the Caffeine page
	Power Output	Improves (the measure goes up)		3 studies	79 people
Studies that measured power output Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained menPLoS One · PMID 22496767 Effect of two doses of caffeine on muscular function during isokinetic exerciseMed Sci Sports Exerc · PMID 20421833 Dose effect of caffeine on testosterone and cortisol responses to resistance exerciseInt J Sport Nutr Exerc Metab · PMID 18458357
	Blood Pressure	Changes; see studies		2 studies	12 people
Studies that measured blood pressure Effects of caffeinated and decaffeinated coffee on biological risk factors for type 2 diabetes: a randomized controlled trialNutr J · PMID 21914162 Genetic determinants of blood pressure responses to caffeine drinkingAm J Clin Nutr · PMID 22170367
	Cortisol	Changes; see studies		1 study	40 people
Studies that measured cortisol Caffeinated coffee does not acutely affect energy intake, appetite, or inflammation but prevents serum cortisol concentrations from falling in healthy menJ Nutr · PMID 21346100
	Subjective Well-Being	Improves (the measure goes up)		1 study	13 people
	Training Volume	Improves (the measure goes up)		1 study	29 people
	Metabolic Rate	Improves (the measure goes up)			12 people
	Testosterone	Improves (the measure goes up)			40 people

Arginine

Blood Flow: improves
Heart Rate: changes; see studies
Vascular Function: improves

Arginine: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Blood Flow Small Increase	Improves (the measure goes up)	Small effect	1 study	17 people
Studies that measured blood flow Restoring vascular nitric oxide formation by L-arginine improves the symptoms of intermittent claudication in patients with peripheral arterial occlusive diseaseJ Am Coll Cardiol · PMID 9809945
	Heart Rate	Changes; see studies		1 study	33 people
Studies that measured heart rate Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained menJ Int Soc Sports Nutr · PMID 22510253
	Vascular Function	Improves (the measure goes up)		1 study	17 people
Studies that measured vascular function Hemodynamic and vascular response to resistance exercise with L-arginineMed Sci Sports Exerc · PMID 19276857
	Blood Pressure	Changes; see studies			17 people
	Power Output	Improves (the measure goes up)			16 people

Vitamin D

Interleukin 5: improves
Power Output: improves

Vitamin D: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Interleukin 5 Small Increase	Improves (the measure goes up)	Small effect	1 study	30 people
Studies that measured interleukin 5 Different doses of supplemental vitamin D maintain interleukin-5 without altering skeletal muscle strength: a randomized, double-blind, placebo-controlled study in vitamin D sufficient adultsNutr Metab · PMID 22405472
	Power Output	Improves (the measure goes up)		1 study	20 people
Studies that measured power output A systems-based investigation into vitamin D and skeletal muscle repair, regeneration, and hypertrophyAm J Physiol Endocrinol Metab · PMID 26506852

Alpha-GPC

Growth Hormone: improves
Power Output: improves

Alpha-GPC: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People
	Growth Hormone Small Increase	Improves (the measure goes up)	Small effect	1 study	7 people
Studies that measured growth hormone Glycerophosphocholine enhances growth hormone secretion and fat oxidation in young adultsNutrition · PMID 22673596
	Power Output	Improves (the measure goes up)			7 people

Spirulina

Muscle Soreness
Power Output: improves

Spirulina: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Muscle Soreness Mixed effect			1 study	24 people
	Power Output	Improves (the measure goes up)		1 study	24 people

Whey Protein

Anti-Oxidant Enzyme Profile: improves
Insulin: changes; see studies
Muscle Mass: improves

Whey Protein: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anti-Oxidant Enzyme Profile Small Increase	Improves (the measure goes up)	Small effect		30 people
Insulin	Changes; see studies		7 studies	17 people
Muscle Mass	Improves (the measure goes up)		5 studies	157 people
Weight	Changes; see studies		4 studies	40 people
Body Fat	Changes; see studies		2 studies	91 people
High-density lipoprotein (HDL)	Improves (the measure goes up)		2 studies	30 people
Muscle protein synthesis (MPS)	Improves (the measure goes up)		2 studies	33 people
Strength	Improves (the measure goes up)		2 studies	132 people
Blood Pressure	Changes; see studies		1 study	30 people
Bone Mineral Density	Improves (the measure goes up)		1 study	36 people
Heart Rate	Changes; see studies			48 people
IGF-1	Improves (the measure goes up)			17 people
Peak power output (PPO)	Improves (the measure goes up)			48 people
Power Output	Improves (the measure goes up)			84 people
Rating of Perceived Exertion	Improves (the measure goes up)			66 people
Respiratory Exchange Ratio	Improves (the measure goes up)			48 people

Fenugreek

Body Fat: improves
Estrogen: changes; see studies
DHT: improves

Fenugreek: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat Small Decrease	Improves (the measure goes down)	Small effect		30 people
Estrogen	Changes; see studies		2 studies	201 people
DHT	Improves (the measure goes up)			30 people
Free Testosterone	Improves (the measure goes up)			305 people
Muscle Mass	Improves (the measure goes up)			179 people
Strength	Improves (the measure goes up)			264 people
Testosterone	Improves (the measure goes up)			305 people

Arachidonic Acid

Anaerobic Capacity: improves
Power Output: improves
Body Fat: changes; see studies

Arachidonic Acid: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anaerobic Capacity Small Improvement	Improves (the measure goes up)	Small effect		31 people
Power Output	Improves (the measure goes up)		1 study	31 people
Body Fat	Changes; see studies			31 people
Cortisol	Changes; see studies			31 people
Muscle Mass	Improves (the measure goes up)			31 people
Testosterone	Improves (the measure goes up)			31 people

D-Ribose

Creatine Kinase: improves
Oxidative Stress Biomarkers: changes; see studies
Lactate Dehydrogenase: improves

D-Ribose: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Creatine Kinase Small Decrease	Improves (the measure goes down)	Small effect		21 people
Oxidative Stress Biomarkers	Changes; see studies		2 studies	21 people
Lactate Dehydrogenase	Improves (the measure goes up)			21 people
Muscle Soreness	Changes; see studies			21 people
Muscle Strength	Improves (the measure goes up)			21 people
Myoglobin	Improves (the measure goes up)			21 people

Conjugated Linoleic Acid

Body Fat
Weight: changes; see studies
Muscle Mass: improves

Conjugated Linoleic Acid: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect	7 studies	76 people
Weight	Changes; see studies		6 studies	76 people
Muscle Mass	Improves (the measure goes up)		5 studies	76 people

Tribulus Terrestris

Body Fat
Testosterone: improves
Fatigue Symptoms: changes; see studies

Tribulus Terrestris: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect	2 studies	37 people
Testosterone	Improves (the measure goes up)		3 studies	22 people
Fatigue Symptoms	Changes; see studies			15 people
Muscle Mass	Improves (the measure goes up)			37 people
Power Output	Improves (the measure goes up)			37 people

Fish Oil

Anaerobic Capacity
Muscle Mass: improves
Sprint Performance Metrics: improves

Fish Oil: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anaerobic Capacity No effect		NoneNo effect	1 study	26 people
Muscle Mass	Improves (the measure goes up)		1 study	408 people
Sprint Performance Metrics	Improves (the measure goes up)			26 people
Strength	Improves (the measure goes up)			1,229 people

Glutamine

Body Fat
Muscle Mass: improves
Power Output: improves

Glutamine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect	1 study	40 people
Muscle Mass	Improves (the measure goes up)			40 people
Power Output	Improves (the measure goes up)			40 people

Nicotinamide Mononucleotide

Muscle Mass
Walking Ability: improves
Strength: improves

Nicotinamide Mononucleotide: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Muscle Mass No effect		NoneNo effect	1 study	108 people
Walking Ability	Improves (the measure goes up)		1 study	109 people
Strength	Improves (the measure goes up)			146 people

Velvet Antler

Aerobic Exercise Metrics
Testosterone: improves
Erythropoietin: improves

Velvet Antler: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Aerobic Exercise Metrics No effect		NoneNo effect	1 study	38 people
Testosterone	Improves (the measure goes up)		1 study	38 people
Erythropoietin	Improves (the measure goes up)			38 people
IGF-1	Improves (the measure goes up)			38 people
Muscle Mass	Improves (the measure goes up)			38 people
Power Output	Improves (the measure goes up)			38 people
Red Blood Cell Count	Improves (the measure goes up)			38 people

Citrulline

Anaerobic Capacity
Blood Pressure: changes; see studies
Blood Lactate (Exercise): changes; see studies

Citrulline: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anaerobic Capacity No effect		NoneNo effect		21 people
Blood Pressure	Changes; see studies		7 studies	28 people
Blood Lactate (Exercise)	Changes; see studies		6 studies	98 people
Heart Rate	Changes; see studies		4 studies	28 people
Power Output	Improves (the measure goes up)		3 studies	198 people
Muscle Soreness	Changes; see studies		2 studies	62 people
Muscular Endurance	Improves (the measure goes up)		2 studies	103 people
Body Fat	Changes; see studies		1 study	75 people
Rating of Perceived Exertion	Improves (the measure goes up)		1 study	15 people
Weight	Changes; see studies		1 study	75 people
Bilirubin	Changes; see studies			75 people
Fatigue Symptoms	Changes; see studies			59 people
Hemoglobin	Improves (the measure goes up)			75 people
Hydration (Total Body Water)	Improves (the measure goes up)			75 people
Kidney Function	Improves (the measure goes up)			75 people
Liver Enzymes	Changes; see studies			75 people
Muscle Mass	Improves (the measure goes up)			75 people
Muscle Oxygenation	Improves (the measure goes up)			18 people
Red Blood Cell Count	Improves (the measure goes up)			75 people
Serum Albumin	Improves (the measure goes up)			75 people
Strength	Improves (the measure goes up)			21 people
Training Volume	Improves (the measure goes up)			41 people
Urea	Improves (the measure goes up)			102 people
White Blood Cell Count	Improves (the measure goes up)			75 people

HMB

Anaerobic Capacity
Muscle Mass: improves
Muscle Soreness: changes; see studies

HMB: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anaerobic Capacity No effect		NoneNo effect		28 people
Muscle Mass	Improves (the measure goes up)		8 studies	737 people
Muscle Soreness	Changes; see studies		2 studies	26 people
Power Output	Improves (the measure goes up)		2 studies	187 people
Body Fat	Changes; see studies		1 study	448 people
High-density lipoprotein (HDL)	Improves (the measure goes up)		1 study	28 people
Liver Enzymes	Changes; see studies		1 study	68 people
Muscle Damage	Changes; see studies		1 study	387 people
Strength	Improves (the measure goes up)		1 study	1,935 people
Bone Mineral Density	Improves (the measure goes up)			68 people
Cortisol	Changes; see studies			26 people
Fatigue Symptoms	Changes; see studies			63 people
Food Intake	Changes; see studies			125 people
Low-density lipoprotein (LDL)	Changes; see studies			28 people
Testosterone	Improves (the measure goes up)			26 people
Total cholesterol	Changes; see studies			28 people
Training Volume	Improves (the measure goes up)			63 people
Weight	Changes; see studies			193 people

Betaine

Anaerobic Capacity
Power Output: improves
IGF-1: improves

Betaine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Anaerobic Capacity No effect		NoneNo effect		24 people
Power Output	Improves (the measure goes up)		5 studies	82 people
IGF-1	Improves (the measure goes up)		1 study	12 people
Muscle Mass	Improves (the measure goes up)		1 study	34 people
Weight	Changes; see studies		1 study	34 people
Blood Lactate (Exercise)	Changes; see studies			25 people
Body Fat	Changes; see studies			34 people
Cortisol	Changes; see studies			12 people
Fatigue Symptoms	Changes; see studies			35 people
Growth Hormone	Improves (the measure goes up)			12 people
Heart Rate	Changes; see studies			13 people
Insulin	Changes; see studies			12 people
Muscle Creatine Content	Improves (the measure goes up)			34 people
Muscle Oxygenation	Improves (the measure goes up)			13 people
Muscle Soreness	Changes; see studies			24 people
Muscular Endurance	Improves (the measure goes up)			37 people
Nitric Oxide	Improves (the measure goes up)			13 people
Oxidative Stress Biomarkers	Changes; see studies			13 people
Rating of Perceived Exertion	Improves (the measure goes up)			37 people
Training Volume	Improves (the measure goes up)			13 people

DHEA

Body Fat
Estrogen: changes; see studies
Testosterone: improves

DHEA: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		39 people
Estrogen	Changes; see studies		8 studies	89 people
Testosterone	Improves (the measure goes up)		3 studies	129 people
Muscle Mass	Improves (the measure goes up)		2 studies	129 people
Serum DHEA	Improves (the measure goes up)		2 studies	109 people
Cortisol	Changes; see studies		1 study	50 people
Libido	Improves (the measure goes up)		1 study	50 people
Power Output	Improves (the measure goes up)		1 study	69 people
Subjective Well-Being	Improves (the measure goes up)		1 study	50 people
Follicle-Stimulating Hormone	Improves (the measure goes up)			19 people
Functionality in Elderly or Injured	Improves (the measure goes up)			50 people
Liver Enzymes	Changes; see studies			40 people
Luteinizing Hormone	Improves (the measure goes up)			19 people
Prostate-Specific Antigen	Improves (the measure goes up)			40 people
Sex Hormone Binding Globulin	Improves (the measure goes up)			50 people
Sleep Quality	Improves (the measure goes up)			50 people
Total cholesterol	Changes; see studies			50 people
Weight	Changes; see studies			20 people

Beta-Alanine

Cortisol
Muscular Endurance: improves
Power Output: improves

Beta-Alanine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Cortisol No effect		NoneNo effect		8 people
Muscular Endurance	Improves (the measure goes up)		5 studies	8 people
Power Output	Improves (the measure goes up)		3 studies	8 people
Fatigue Symptoms	Changes; see studies			51 people
Growth Hormone	Improves (the measure goes up)			8 people
Testosterone	Improves (the measure goes up)			8 people

Tongkat Ali

Bilirubin
Strength: improves
Uric Acid: changes; see studies

Tongkat Ali: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Bilirubin No effect		NoneNo effect		13 people
Strength	Improves (the measure goes up)		2 studies	40 people
Uric Acid	Changes; see studies		1 study	13 people
Blood Urea Nitrogen	Improves (the measure goes up)			13 people
Creatinine	Improves (the measure goes up)			13 people
Gamma-Glutamyltransferase	Improves (the measure goes up)			13 people
Kidney Function	Improves (the measure goes up)			13 people
Liver Enzymes	Changes; see studies			13 people
Power Output	Improves (the measure goes up)			40 people
Urea	Improves (the measure goes up)			13 people
Urinary Albumin	Improves (the measure goes up)			13 people

Anatabine

Blood Pressure
Heart Rate: changes; see studies
Muscle Damage: changes; see studies

Anatabine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Blood Pressure No effect		NoneNo effect		20 people
Heart Rate	Changes; see studies		1 study	20 people
Muscle Damage	Changes; see studies			20 people
Muscle Soreness	Changes; see studies			20 people
Power Output	Improves (the measure goes up)			20 people

Boron

Body Fat
Testosterone: improves
Free Testosterone: improves

Boron: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		19 people
Testosterone	Improves (the measure goes up)		1 study	19 people
Free Testosterone	Improves (the measure goes up)			19 people
Muscle Mass	Improves (the measure goes up)			19 people
Strength	Improves (the measure goes up)			19 people

Calcium

Free Testosterone
Testosterone: improves

Calcium: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Free Testosterone No effect		NoneNo effect		30 people
	Testosterone	Improves (the measure goes up)		1 study	30 people

D-Aspartic Acid

Body Fat
Testosterone: improves
Estrogen: changes; see studies

D-Aspartic Acid: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		20 people
Testosterone	Improves (the measure goes up)		2 studies	20 people
Estrogen	Changes; see studies			20 people
Muscle Mass	Improves (the measure goes up)			20 people
Power Output	Improves (the measure goes up)			20 people
Weight	Changes; see studies			20 people

Ecdysteroids

Cortisol
Testosterone: improves
Liver Enzymes: changes; see studies

Ecdysteroids: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Cortisol No effect		NoneNo effect		45 people
Testosterone	Improves (the measure goes up)		1 study	45 people
Liver Enzymes	Changes; see studies			45 people
Muscle Mass	Improves (the measure goes up)			45 people
Power Output	Improves (the measure goes up)			45 people
Total cholesterol	Changes; see studies			45 people
Triglycerides	Changes; see studies			45 people

Ephedrine

Power Output
Subjective Well-Being: improves

Ephedrine: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Power Output No effect		NoneNo effect		8 people
	Subjective Well-Being	Improves (the measure goes up)		1 study	8 people

Gamma Oryzanol

Cortisol
High-density lipoprotein (HDL): improves
Power Output: improves

Gamma Oryzanol: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Cortisol No effect		NoneNo effect		22 people
High-density lipoprotein (HDL)	Improves (the measure goes up)		1 study	22 people
Power Output	Improves (the measure goes up)		1 study	22 people
Estrogen	Changes; see studies			22 people
Growth Hormone	Improves (the measure goes up)			22 people
Insulin	Changes; see studies			22 people
Plasma Endorphins	Improves (the measure goes up)			22 people
Testosterone	Improves (the measure goes up)			22 people
Total cholesterol	Changes; see studies			22 people
Triglycerides	Changes; see studies			22 people

L-Tyrosine

Adrenocorticotropic Hormone
Aerobic Exercise Metrics: improves
Blood Lactate (Exercise): changes; see studies

L-Tyrosine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	People
Adrenocorticotropic Hormone No effect		NoneNo effect	20 people
Aerobic Exercise Metrics	Improves (the measure goes up)		20 people
Blood Lactate (Exercise)	Changes; see studies		20 people
Cortisol	Changes; see studies		20 people
Fatigue Symptoms	Changes; see studies		20 people
Muscular Endurance	Improves (the measure goes up)		20 people
Strength	Improves (the measure goes up)		20 people
Subjective Well-Being	Improves (the measure goes up)		20 people

Leucic Acid

Anaerobic Capacity
Body Fat: changes; see studies
Bone Mineral Density: improves

Leucic Acid: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	People
Anaerobic Capacity No effect		NoneNo effect	15 people
Body Fat	Changes; see studies		15 people
Bone Mineral Density	Improves (the measure goes up)		15 people
Muscle Mass	Improves (the measure goes up)		15 people
Muscle Soreness	Changes; see studies		15 people
Power Output	Improves (the measure goes up)		15 people
Weight	Changes; see studies		15 people

Leucine

Body Fat
Rating of Perceived Exertion: improves
Liver Enzymes: changes; see studies

Leucine: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		26 people
Rating of Perceived Exertion	Improves (the measure goes up)		1 study	26 people
Liver Enzymes	Changes; see studies			26 people
Muscle Mass	Improves (the measure goes up)			26 people
Power Output	Improves (the measure goes up)			26 people

Terminalia Arjuna

Anaerobic Capacity
Power Output: improves

Terminalia Arjuna: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Anaerobic Capacity No effect		NoneNo effect		40 people
	Power Output	Improves (the measure goes up)			40 people

Ursolic Acid

Body Fat
IGF-1: improves
Insulin: changes; see studies

Ursolic Acid: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		16 people
IGF-1	Improves (the measure goes up)		1 study	16 people
Insulin	Changes; see studies			16 people
Irisin	Improves (the measure goes up)			16 people
Muscle Mass	Improves (the measure goes up)			16 people
Power Output	Improves (the measure goes up)			16 people

Bitter orange

Carbohydrate Oxidation: improves

Bitter orange: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Carbohydrate Oxidation	Improves (the measure goes up)		6 studies	12 people

Cannabis

Heart Rate: changes; see studies
Aerobic Exercise Metrics: worsens
Blood Pressure: changes; see studies

Cannabis: outcomes studied for Muscle Size & Strength
Outcome	Effect	Size	Studies	People
Heart Rate	Changes; see studies		4 studies	20 people
Aerobic Exercise Metrics Small Detriment	Worsens (the measure goes down)	Small effect	1 study	20 people
Blood Pressure	Changes; see studies		1 study	20 people
Blood Flow	Improves (the measure goes up)			20 people
Power Output	Improves (the measure goes up)			20 people

Iron

Muscular Endurance: improves

Iron: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Muscular Endurance	Improves (the measure goes up)		1 study	20 people

Magnesium

Strength: improves

Magnesium: outcomes studied for Muscle Size & Strength
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Strength	Improves (the measure goes up)		1 study	26 people

What the published studies found

19 automated readings

Automated reading of the published studies (Decosa evidence engine), for outcomes Dr. Grey has not graded yet. It is not a Dr. Grey grade and does not change one. How it is read

Ashwagandha: muscle strength
The studies disagree. The best available review (2026, 3 studies, 161 people) did not settle it for muscle strength, while 8 of the 10 studies read found an improvement. The evidence is very weak.
10 studies counted of 11 read: 4 reviews and 6 trials (300 people in the trials).
1. Meta-analysis, 2026; 3 studies, 161 people; healthy adults undergoing resistance training: unclear: evidence too weak to tell (the review the verdict rests on). associated with greater gains than placebo in 1-RM bench press Adjunctive Ashwagandha (Withania somnifera) Supplementation and Resistance-Training Adaptations in Healthy Adults: A Systematic Review and Random-Effects Meta-Analysis of Muscular Strength, Chest Circumference, and Body CompositionPubMed 42738987
2. Systematic review, 2026; 20 studies, 1,249 people: improves. muscle strength (SMD = 0.58; 95% CI: 0.12-1.04; P = 0.013; I2 = 56.9%) Effects of Withania somnifera (L.) Dunal (Ashwagandha) on cognitive and physical function in adults: a systematic review and meta-analysisPubMed 42199854
3. Meta-analysis, 2026; 13 studies, 599 people; young adults or athletes: unclear: evidence too weak to tell. strength effects were positive but uncertain Effects of Withania somnifera (Ashwagandha) Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-AnalysisPubMed 42356302
4. Systematic review, 2026; 24 studies; healthy individuals and patients with stress-related or functional disorders: improves. Reported benefits included reduction of stress and anxiety, alleviation of depressive symptoms, improved sleep quality, … Clinical evidence for the adaptogenic effects of Withania somnifera and Rhodiola rosea - A systematic review with molecular interpretation of psychometric outcomesPubMed 41906501
5. Randomised trial, 2026; 83 people; recreationally active healthy adults aged 25-50: improves. significantly greater improvements in muscle strength Efficacy and safety of a sustained release ashwagandha root extract capsules on muscle strength and cardiorespiratory endurance in recreationally active individuals: a randomized, double-blind, placebo-controlled trialPubMed 42780946
6. Randomised trial, 2026; 56 people; team sports athletes during pre-season training: improves. Countermovement Jump (CMJ) improved significantly in ASH Ashwagandha Root Extract Stabilises Physiological Stress Responses in Male and Female Team Sports Athletes During Pre-Season TrainingPubMed 41599843
7. Randomised trial, 2026; 31 people; male amateur handball players: improves. significantly improved handgrip strength compared with placebo Effects of 8 days of Ashwagandha supplementation on strength, fatigue, soreness, and recovery in amateur handball players: A double-blind, randomized, placebo-controlled trialPubMed 41940566
8. Randomised trial, 2024; healthy volunteers: improves. Evaluation of Withania somnifera (L.) Dunal (Ashwagandha) on Physical Performance, Biomarkers of Inflammation, and Muscle Status in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled StudyPubMed 39381480
9. Randomised trial, 2023; 73 people; healthy adults performing resistance training: improves. AG caused greater improvement in bench press Effects of Ashwagandha ( Withania somnifera) standardized root extract on physical endurance and VO 2max in healthy adults performing resistance training: An eight-week, prospective, randomized, double-blind, placebo-controlled studyPubMed 38988644
10. Randomised trial, 2015; 57 people; healthy young men engaged in resistance training: improves. significantly greater increases in muscle strength on the bench-press exercise Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trialPubMed 26609282
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Beta-Alanine: endurance performance
The best available review (2026, 52 studies) found little or no difference in endurance performance. That review studied healthy adult athletes. 5 of the 9 studies read agree; 4 found an improvement. The evidence is moderate.
9 studies counted of 11 read: 3 reviews and 6 trials (116 people in the trials).
1. Systematic review, 2026; 52 studies; healthy adult athletes: no clear difference (the review the verdict rests on). BA supplementation produced non-significant or context-specific effects Effects of combined versus single supplementation of creatine and beta-alanine on aerobic and anerobic performance: a systematic review and network meta-analysisPubMed 42384726
2. Systematic review, 2014; 20 studies; athletic population: improves. BA may increase power output and working capacity The effects of beta-alanine supplementation on performance: a systematic review of the literaturePubMed 23918656
3. Meta-analysis, 2012; 15 studies, 360 people: no clear difference. BA improved (P=0.002) the outcome of exercise measures Effects of β-alanine supplementation on exercise performance: a meta-analysisPubMed 22270875
4. Randomised trial, 2026; 22 people; young resistance-trained men and women: improves. total number of repetitions increased with BA Beta-Alanine Supplementation Improves Isotonic Strength Endurance Performance Without Altering Psychological Responses During Drop-Set and Bi-Set Resistance Exercises in Resistance-Trained IndividualsPubMed 42413109
5. Randomised trial, 2025; 27 people; adolescent middle- and long-distance runners: improves. increased TTE by 6.5% compared to 1.4% Beta-alanine supplementation improves time to exhaustion, but not aerobic capacity, in competitive middle- and long-distance runnersPubMed 40528157
6. Randomised trial, 2021; 16 people; long-distance runners: no clear difference. No significant differences were shown for the 5000 m running time Beta-alanine fails to improve on 5000 m running time despite increasing PAT1 expression in long-distance runnersPubMed 33305552
7. Randomised trial, 2018; 16 people; physically active adults: improves. statistically significant difference between the β-alanine vs placebo group Beta-Alanine Supplementation Improved 10-km Running Time Trial in Physically Active AdultsPubMed 30135662
8. Randomised trial, 2016; 14 people; aerobically trained males: no clear difference. Thirty days of β-alanine supplementation (SUPP) did not increase VO2 peak (4.05 ± 0.6 vs. … β-alanine Supplementation Fails to Increase Peak Aerobic Power or Ventilatory Threshold in Aerobically Trained MalesPubMed 25299148
9. Randomised trial, 2013; 21 people; anaerobically trained college-aged men: no clear difference. did not have a significant effect on sprint endurance Effects of beta-alanine supplementation on sprint endurancePubMed 22476168
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Beta-Alanine: muscle mass
The best available review (2022, 20 studies, 492 people) found little or no difference in muscle mass. All 5 studies read agree. The evidence is limited.
5 studies counted of 10 read: 3 reviews and 2 trials (42 people in the trials).
1. Meta-analysis, 2022; 20 studies, 492 people: no clear difference (the review the verdict rests on). fat-free mass (FFM) (WMD: 0.05 kg Effects of beta-alanine supplementation on body composition: a GRADE-assessed systematic review and meta-analysisPubMed 35813845
2. Systematic review, 2025; 35 studies, 991 people; athletes completing strength and conditioning training: no clear difference. Effects of different dietary supplements combined with conditioning training on muscle strength, jump performance, sprint speed, and muscle mass in athletes: a systematic review and network meta-analysisPubMed 40717998
3. Systematic review, 2023; 7 studies; combat athletes: no clear difference. non-significant (p > 0.05) improvement in the anthropometric parameters of lean mass β-Alanine Supplementation in Combat Sports: Evaluation of Sports Performance, Perception, and Anthropometric Parameters and Biochemical Markers-A Systematic Review of Clinical TrialsPubMed 37686787
4. Randomised trial, 2016; 16 people; untrained collegiate females: no clear difference. no additive effects on body composition Effects of β-Alanine on Body Composition and Performance Measures in Collegiate WomenPubMed 25486294
5. Randomised trial, 2008; 26 people; vietnamese sports science students: no clear difference. no significant effect of beta-ala supplementation on any of the exercise parameters measured, mass The effects of 10 weeks of resistance training combined with beta-alanine supplementation on whole body strength, force production, muscular endurance and body compositionPubMed 18175046
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Beta-Alanine: exercise performance
The studies disagree. The best available review (2025, 5 studies, 163 people) found an improvement in exercise performance, while 4 of the 8 studies read found no clear difference. The evidence is very weak.
8 studies counted of 9 read: 5 reviews and 3 trials (54 people in the trials).
1. Systematic review, 2025; 5 studies, 163 people; older adults: improves (the review the verdict rests on). exercise capacity may be improved following supplementation Beta-Alanine for Improving Exercise Capacity, Muscle Strength, and Functional Performance of Older Adults: A Systematic ReviewPubMed 39724872
2. Meta-analysis, 2024; 18 studies, 331 people; trained young male individuals: improves. overall effect size of 0.39 (95% confidence interval [CI] [0.09, 0.69]) Effect of Beta-Alanine Supplementation on Maximal Intensity Exercise in Trained Young Male Individuals: A Systematic Review and Meta-AnalysisPubMed 39032921
3. Meta-analysis, 2024; 10 studies, 243 people; healthy adults of any training status: no clear difference. No ergogenic effect was detected in this meta-analysis for BA Sodium bicarbonate and beta-alanine supplementation: Is combining both better than either alone? A systematic review and meta-analysisPubMed 38952910
4. Systematic review, 2017; 23 studies; athletes and non-athletes: no clear difference. Effects of beta-alanine supplementation on performance and muscle fatigue in athletes and non-athletes of different sports: a systematic reviewPubMed 27377257
5. Meta-analysis, 2012; 15 studies, 360 people: no clear difference. BA improved (P=0.002) the outcome of exercise measures Effects of β-alanine supplementation on exercise performance: a meta-analysisPubMed 22270875
6. Randomised trial, 2026; 22 people; young resistance-trained men and women: improves. total number of repetitions increased with BA Beta-Alanine Supplementation Improves Isotonic Strength Endurance Performance Without Altering Psychological Responses During Drop-Set and Bi-Set Resistance Exercises in Resistance-Trained IndividualsPubMed 42413109
7. Randomised trial, 2021; 16 people; long-distance runners: no clear difference. No significant differences were shown for the 5000 m running time Beta-alanine fails to improve on 5000 m running time despite increasing PAT1 expression in long-distance runnersPubMed 33305552
8. Randomised trial, 2018; 16 people; physically active adults: improves. statistically significant difference between the β-alanine vs placebo group Beta-Alanine Supplementation Improved 10-km Running Time Trial in Physically Active AdultsPubMed 30135662
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Caffeine: muscle strength
The best available review (2026, 21 studies) found a small improvement in muscle strength. That review studied athletes or individuals testing muscular strength. 7 of the 8 studies read agree; 1 found no clear difference. The evidence is moderate.
8 studies counted of 8 read: 6 reviews and 2 trials (56 people in the trials).
1. Meta-analysis, 2026; 21 studies; athletes or individuals testing muscular strength: improves (the review the verdict rests on). ergogenic effect of caffeinated chewing gum was found for muscular strength Fast-Acting Caffeine: Does Caffeinated Chewing Gum Enhance Muscular Strength, Endurance, and Jumping Performance? A Systematic Review and Meta-AnalysisPubMed 42228847
2. Meta-analysis, 2024; 14 studies: improves. significantly improved muscle strength (WMD, 7.09 Effects of Acute Ingestion of Caffeine Capsules on Muscle Strength and Muscle Endurance: A Systematic Review and Meta-AnalysisPubMed 38674836
3. Meta-analysis, 2024; 9 studies; athletes: improves. The effect of caffeine supplementation on muscular strength and endurance: A meta-analysis of meta-analysesPubMed 39170391
4. Meta-analysis, 2021; 8 studies: improves. Ergogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-AnalysisPubMed 34072182
5. Meta-analysis, 2019; 10 studies: improves. SMD for the effects of caffeine on strength was 0.16 The effects of caffeine ingestion on isokinetic muscular strength: A meta-analysisPubMed 30217692
6. Meta-analysis, 2010; 27 studies: improves. small beneficial effect on MVC strength Effect of caffeine ingestion on muscular strength and endurance: a meta-analysisPubMed 20019636
7. Crossover trial, 2025; 13 people; resistance-trained males: improves. caffeine increased mean velocity (Vmean) and power output Acute caffeine intake improves muscular strength, power, and endurance performance, reversing the time-of-day effect regardless of muscle activation level in resistance-trained males: a randomized controlled trialPubMed 40478455
8. Crossover trial, 2023; 43 people; younger and older men: no clear difference. No effects of caffeine ingestion on peak torque Exogenous Caffeine Ingestion Does Not Increase Plantarflexor Torque in Older or Younger MenPubMed 36640779
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Citrulline: endurance performance
Mixed or unclear: two readings of the studies disagreed. One reading found evidence too weak to tell for endurance performance, the other an improvement. The question is open.
7 studies counted of 9 read: 4 reviews and 3 trials (37 people in the trials).
1. Meta-analysis, 2026; 30 studies, 644 people: unclear: evidence too weak to tell (the review the verdict rests on). small improvement in overall exercise performance (g = 0.16, p = 0.01) Effects of Citrulline Malate Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-AnalysisPubMed 42356270
2. Meta-analysis, 2023; 9 studies, 158 people; young healthy adults: no clear difference. no significant difference in the endurance performance measures Effects of citrulline on endurance performance in young healthy adults: a systematic review and meta-analysisPubMed 37155582
3. Meta-analysis, 2022; 10 studies: no clear difference. no positive effects of Cit supplementation on aerobic performance Effects of Citrulline Supplementation on Different Aerobic Exercise Performance Outcomes: A Systematic Review and Meta-AnalysisPubMed 36079738
4. Meta-analysis, 2021; 3 studies: no clear difference. No effect on exercise performance following consumption of foods rich in L-citrulline Effect of food sources of nitrate, polyphenols, L-arginine and L-citrulline on endurance exercise performance: a systematic review and meta-analysis of randomised controlled trialsPubMed 34965876
5. Crossover trial, 2025; 20 people: no clear difference. no statistically significant difference in TTE Ergogenic effects of a 10-day L-citrulline supplementation on time to exhaustion and cardiorespiratory and metabolic responses in healthy individuals: a double-blind, randomised, placebo-controlled crossover trialPubMed 40980088
6. Crossover trial, 2020; 9 people; nine trained male cyclists: no clear difference. improvement in TT time of 5.2% One Week of L-Citrulline Supplementation Improves Performance in Trained CyclistsPubMed 31860534
7. Crossover trial, 2016; 8 people; healthy recreationally-active adult males: no clear difference. was not significantly different between conditions Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humansPubMed 27378312
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Citrulline: muscle strength
Mixed or unclear: two readings of the studies disagreed. One reading found an improvement for muscle strength, the other evidence too weak to tell. The question is open.
8 studies counted of 10 read: 4 reviews and 4 trials (164 people in the trials).
1. Systematic review, 2026; 12 studies, 360 people; postmenopausal women: unclear: evidence too weak to tell (the review the verdict rests on). suggesting improvements only when citrulline was combined Citrulline supplementation in postmenopausal women: a systematic review of vascular, muscular, and metabolic effectsPubMed 41588439
2. Meta-analysis, 2022; 4 studies, 138 people; resistance-trained adults: no clear difference. did not observe an overall effect favoring citrulline-malate supplementation Effects of Citrulline Malate Supplementation on Muscle Strength in Resistance-Trained Adults: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsPubMed 34176406
3. Systematic review, 2020; 6 studies, 250 people; older adults aged 50 years and older: improves. four of six studies reported CIT effects on muscle strength Effects of Citrulline alone or combined with exercise on muscle mass, muscle strength, and physical performance among older adults: a systematic reviewPubMed 31714265
4. Meta-analysis, 2019; 12 studies, 198 people; healthy men and women: improves. significant benefit for citrulline compared to placebo treatments Acute Effects of Citrulline Supplementation on High-Intensity Strength and Power Performance: A Systematic Review and Meta-AnalysisPubMed 30895562
5. Crossover trial, 2025; 43 people; young, trained men and women: no clear difference. did not enhance maximal neuromuscular performance Malate or Not? Acute Effects of L-Citrulline Versus Citrulline Malate on Neuromuscular Performance in Young, Trained Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover TrialPubMed 39662304
6. Crossover trial, 2022; 24 people; hypertensive postmenopausal women: improves. Leg curl strength increased greater with CIT Combined L-Citrulline Supplementation and Slow Velocity Low-Intensity Resistance Training Improves Leg Endothelial Function, Lean Mass, and Strength in Hypertensive Postmenopausal WomenPubMed 36615732
7. Randomised trial, 2020; 24 people; healthy young individuals: improves. significantly larger increase in maximal knee extensor strength Synergetic Effect of NO Precursor Supplementation and Exercise TrainingPubMed 33064413
8. Randomised trial, 2019; 73 people; sedentary obese older men and women: improves. Initial Dietary Protein Intake Influence Muscle Function Adaptations in Older Men and Women Following High-Intensity Interval Training Combined with CitrullinePubMed 31336654
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Collagen Peptides: muscle strength
The best available review (2024, 19 studies, 768 people) found an improvement in muscle strength. That review studied healthy adults over 17 years. 5 of the 9 studies read agree; 4 found no clear difference. The evidence is limited.
9 studies counted of 11 read: 2 reviews and 7 trials (350 people in the trials).
1. Meta-analysis, 2024; 19 studies, 768 people; healthy adults over 17 years: improves (the review the verdict rests on). Impact of Collagen Peptide Supplementation in Combination with Long-Term Physical Training on Strength, Musculotendinous Remodeling, Functional Recovery, and Body Composition in Healthy Adults: A Systematic Review with Meta-analysisPubMed 39060741
2. Systematic review, 2021; 15 studies; recreational athletes, elderly, untrained pre-menopausal women: improves. improvements in body composition, strength and muscle recovery The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic reviewPubMed 34491424
3. Randomised trial, 2023; 39 people; young healthy males: no clear difference. did not differ between-groups (0.684 ≤ p ≤ 0.929) The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance trainingPubMed 36433662
4. Randomised trial, 2022; 40 people; healthy male volunteers: no clear difference. muscle strength increased in both groups, with no statistical difference Effects of specific collagen peptide supplementation combined with resistance training on Achilles tendon propertiesPubMed 35403756
5. Randomised trial, 2021; 97 people; middle-aged, untrained men: improves. leg strength (ΔCP-G = 163 ± 189 N; ΔP-G = 100 ± 154 N The Influence of Specific Bioactive Collagen Peptides on Body Composition and Muscle Strength in Middle-Aged, Untrained Men: A Randomized Controlled TrialPubMed 33946565
6. Randomised trial, 2021; 15 people; resistance-trained males: no clear difference. CP supplementation attenuated performance decline 24 hr Effects of Collagen Peptides on Recovery Following Eccentric Exercise in Resistance-Trained Males-A Pilot StudyPubMed 33186897
7. Randomised trial, 2019; 77 people; premenopausal women: improves. significantly higher gain in hand-grip strength Specific Collagen Peptides in Combination with Resistance Training Improve Body Composition and Regional Muscle Strength in Premenopausal Women: A Randomized Controlled TrialPubMed 31010031
8. Randomised trial, 2019; 57 people; recreationally active young men: no clear difference. Prolonged Collagen Peptide Supplementation and Resistance Exercise Training Affects Body Composition in Recreationally Active MenPubMed 31126103
9. Randomised trial, 2019; 25 people; young recreationally active men: improves. slightly higher increase in COL compared with PLA Effects of 12 Weeks of Hypertrophy Resistance Exercise Training Combined with Collagen Peptide Supplementation on the Skeletal Muscle Proteome in Recreationally Active MenPubMed 31091754
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Creatine: muscle mass
Mixed or unclear: two readings of the studies disagreed. One reading found an improvement for muscle mass, the other mixed results. The question is open.
8 studies counted of 10 read: 7 reviews and 1 trial (15 people in the trials).
1. Meta-analysis, 2007; 12 studies, 266 people; people with hereditary muscle disease: mixed results (the review the verdict rests on). increase in lean body mass during creatine treatment Creatine for treating muscle disordersPubMed 17253521
2. Meta-analysis, 2026; 7 studies, 608 people; postmenopausal women: improves. Lean mass (k = 5; n = 338) favored creatine: mean difference (MD) + 0.37 … Creatine monohydrate for lean mass, strength, and bone density in postmenopausal women: a systematic review and meta-analysisPubMed 42141930
3. Systematic review, 2025; 19 studies; combat sport athletes: improves. increased measures of body mass and fat-free mass Creatine Supplementation in Combat Sport Athletes: A Narrative Systematic ReviewPubMed 40755023
4. Meta-analysis, 2025; 61 studies; novice and experienced lifters: improves. significantly increased FFM (weighted mean difference [WMD]: 1.39 kg Creatine supplementation and resistance training: a comparison between novice and experienced lifters - a systematic review and dose-response meta-analysisPubMed 41433021
5. Meta-analysis, 2024; 33 studies, 1,076 people; older adults and adults with chronic disease: improves. lean tissue mass (MD 1.08 kg; 95% CI: 0.77-1.38 Creatine supplementation for optimization of physical function in the patient at risk of functional disability: A systematic review and meta-analysisPubMed 38417175
6. Meta-analysis, 2023; 10 studies; healthy adults: no clear difference. pooled mean estimate of 0.11 (95% Credible Interval (CrI): -0.02 to 0.25) The Effects of Creatine Supplementation Combined with Resistance Training on Regional Measures of Muscle Hypertrophy: A Systematic Review with Meta-AnalysisPubMed 37432300
7. Meta-analysis, 2021; older adults undergoing resistance training: improves. augments lean tissue mass and strength increase Meta-Analysis Examining the Importance of Creatine Ingestion Strategies on Lean Tissue Mass and Strength in Older AdultsPubMed 34199420
8. Randomised trial, 2025; 15 people; healthy vegans and vegetarians: improves. FFM (1.15 ± 0.94 kg, p < 0.05) Muscle creatine levels and sprint performance in young adult vegans and vegetarians after 7 days of creatine monohydrate supplementationPubMed 40939139
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Creatine: muscle strength
A Cochrane review (2013, 14 studies, 364 people) found an improvement in muscle strength. That review studied people with hereditary or acquired muscle diseases. 5 of the 9 studies read agree; 4 found no clear difference. The evidence is strong.
9 studies counted of 10 read: 9 reviews.
1. Meta-analysis, 2013; 14 studies, 364 people; people with hereditary or acquired muscle diseases: improves (the review the verdict rests on). significant increase in muscle strength in the creatine group Creatine for treating muscle disordersPubMed 23740606
2. Systematic review, 2026; 11 studies; older adults aged 60 years and older: improves. significantly improved muscle strength compared with resistance training alone Effects of resistance training combined with creatine supplementation on muscle strength, physical function, and muscle mass in older adults: a systematic review and three-level meta-analysisPubMed 42712402
3. Meta-analysis, 2025; 69 studies, 1,937 people: improves. improvements in bench and chest press strength [WMD = 1.43 kg, p = 0.002] The Effects of Creatine Supplementation on Upper- and Lower-Body Strength and Power: A Systematic Review and Meta-AnalysisPubMed 40944139
4. Meta-analysis, 2025; general population: improves. Cr group exhibited significant strength gains Effects of creatine supplementation on muscle strength gains-a meta-analysis and systematic reviewPubMed 41328071
5. Meta-analysis, 2024; 23 studies, 512 people; adults under 50 years of age: improves. significantly increased upper-body (WMD = 4.43 kg Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-AnalysisPubMed 39519498
6. Meta-analysis, 2021; 13 studies, 278 people; adults undergoing exercise-induced muscle damage: no clear difference. Creatine supplementation did not alter muscle strength, muscle soreness, range of motion, or inflammation at … The Effect of Creatine Supplementation on Markers of Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Human Intervention TrialsPubMed 33631721
7. Meta-analysis, 2012; 12 studies, 38 people; people with confirmed mitochondrial disease: no clear difference. one reporting evidence of improved measures of muscle strength Treatment for mitochondrial disordersPubMed 22513923
8. Meta-analysis, 2010; 4 studies, 151 people; patients with COPD receiving pulmonary rehabilitation: no clear difference. did not improve lower extremity muscle strength Creatine supplementation for patients with COPD receiving pulmonary rehabilitation: a systematic review and meta-analysisPubMed 20497386
9. Systematic review, 2004; 2 studies; adults with facioscapulohumeral muscular dystrophy: no clear difference. non-significant difference in favour of creatine Drug treatment for facioscapulohumeral muscular dystrophyPubMed 15106171
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Creatine: endurance performance
The studies disagree. A Cochrane review (2014, 13 studies, 85 people) found little or no difference in endurance performance, while 2 of the 8 studies read found an improvement. The evidence is very weak.
Possible harm: 1 study read reported a worse result for endurance performance with Creatine. One abstract says: "VO2max increased in both groups but increased less after creatine supplementation than placebo (effect size [ES] = -0.32, 95%CI = -0.51 to -0.12, p = 0.002)." Check the studies below, and ask a doctor or pharmacist if this applies to you.
Side effects: 1 of the 2 studies that reported on them found more with Creatine (myalgia).
8 studies counted of 11 read: 6 reviews and 2 trials (30 people in the trials).
1. Meta-analysis, 2014; 13 studies, 85 people: no clear difference (the review the verdict rests on). There was no benefit with: D-ribose,glucagon, verapamil, vitamin B6, branched chain amino acids, dantrolene sodium, … Pharmacological and nutritional treatment for McArdle disease (Glycogen Storage Disease type V)PubMed 25391139
2. Systematic review, 2025; 19 studies; combat sport athletes: no clear difference. did not influence measures of sport-specific endurance Creatine Supplementation in Combat Sport Athletes: A Narrative Systematic ReviewPubMed 40755023
3. Meta-analysis, 2023; 19 studies, 424 people; young healthy adults, mostly men: worsens. increased less after creatine supplementation than placebo Creatine supplementation and VO2max: a systematic review and meta-analysisPubMed 34859731
4. Meta-analysis, 2023; 13 studies; trained population: no clear difference. non-significant change in endurance performance after creatine monohydrate supplementation Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysisPubMed 36877404
5. Meta-analysis, 2023; 10 studies; people across different age groups: improves. taking Cr supplements demonstrated statistically significant benefits over PLA Effectiveness of Creatine in Metabolic Performance: A Systematic Review and Meta-AnalysisPubMed 37720119
6. Systematic review, 2004; 10 studies: improves. statistically significant benefit, albeit modest, in ischaemic exercise Pharmacological and nutritional treatment for McArdle's disease (Glycogen Storage Disease type V)PubMed 15266486
7. Crossover trial, 2005; 8 people; persons with chronic tetraplegia and weak muscles: no clear difference. no significant differences in MVC, endurance times Creatine supplementation for weak muscles in persons with chronic tetraplegia: a randomized double-blind placebo-controlled crossover trialPubMed 16048138
8. Randomised trial, 2001; 22 people; twenty-two rowers: no clear difference. did not increase performance or training volume over a placebo condition Effects of creatine monohydrate supplementation during combined strength and high intensity rowing training on performancePubMed 11842271
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Fish Oil: muscle strength
The studies read do not show a clear benefit for muscle strength. One reading found evidence too weak to tell, a second reading of the same search found mixed results. The strongest review read studied healthy adults without obesity. The evidence is very weak.
7 studies counted of 11 read: 3 reviews and 4 trials (361 people in the trials).
1. Meta-analysis, 2026; 8 studies; healthy adults without obesity: unclear: evidence too weak to tell (the review the verdict rests on). showed no clear evidence of an effect Omega-3 supplementation shows no clear benefit for fat-free mass or muscle strength in healthy adults: a systematic review and meta-analysis of randomized controlled trialsPubMed 42735611
2. Meta-analysis, 2024; 4 studies: improves. significantly improved muscle strength compared to the placebo-controlled group Effects of Omega-3 fatty acids supplementation and resistance training on skeletal musclePubMed 38777432
3. Meta-analysis, 2020; 12 studies, 291 people: no clear difference. no significant differences in isometric muscle strength Omega-3 Polyunsaturated Fatty Acid Supplementation for Reducing Muscle Soreness after Eccentric Exercise: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsPubMed 32382573
4. Randomised trial, 2023; 20 people; healthy older postmenopausal women: improves. Handgrip strength substantially increased only in RET-FO Fish Oil Supplementation with Resistance Exercise Training Enhances Physical Function and Cardiometabolic Health in Postmenopausal WomenPubMed 37960168
5. Randomised trial, 2022; 200 people; older Chinese people: improves. hand grip strength (interaction time × group effect P < 0.001) Effects of fish oil-derived n-3 polyunsaturated fatty acid on body composition, muscle strength and physical performance in older people: a secondary analysis of a randomised, double-blind, placebo-controlled trialPubMed 36571774
6. Randomised trial, 2022; 34 people; sarcopenic older women aged 65 years or older: improves. significantly greater compared with EP for muscle strength Randomised Controlled Trial of Fish Oil Supplementation on Responsiveness to Resistance Exercise Training in Sarcopenic Older WomenPubMed 35889801
7. Randomised trial, 2021; 107 people; older adults at risk of sarcopenia: no clear difference. Neither LEU-PRO nor LEU-PRO+n-3 supplementation affected appendicular lean mass, handgrip strength Does supplementation with leucine-enriched protein alone and in combination with fish-oil-derived n-3 PUFA affect muscle mass, strength, physical performance, and muscle protein synthesis in well-nourished older adults? A randomized, double-blind, placebo-controlled trialPubMed 33871558
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Iron: endurance performance
The best available review (2025, 23 studies, 669 people) found an improvement in endurance performance. That review studied high-level iron deficient female athletes. 4 of the 6 studies read agree; 1 found no clear difference, 1 found no clear answer. The evidence is moderate.
6 studies counted of 8 read: 5 reviews and 1 trial (166 people in the trials).
1. Systematic review, 2025; 23 studies, 669 people; high-level iron deficient female athletes: improves (the review the verdict rests on). Iron deficiency, supplementation, and sports performance in female athletes: A systematic reviewPubMed 39536912
2. Systematic review, 2025; football players: improves. The efficacy of dietary supplements on health status and performance of football players: a systematic reviewPubMed 39915258
3. Systematic review, 2018; 12 studies, 283 people; iron-deficient nonanemic athletes: unclear: evidence too weak to tell. Supplementing IDNA athletes with iron improved performance in 6 studies (146 participants) and did not … Does Iron Supplementation Improve Performance in Iron-Deficient Nonanemic Athletes?PubMed 29792778
4. Meta-analysis, 2015; 17 studies; iron deficient non-anaemic endurance athletes: improves. moderate effect on improving [Hb] (Hedges' g=0.695, 95% CI 0.533 to 0.836, p<0.001) and (VO(2max)) … Is iron treatment beneficial in, iron-deficient but non-anaemic (IDNA) endurance athletes? A systematic review and meta-analysisPubMed 25361786
5. Systematic review, 2007; 3 studies; children and adolescents: improves. Treadmill endurance time was significantly better in iron Effect of iron supplementation on physical performance in children and adolescents: systematic review of randomized controlled trialsPubMed 17277426
6. Randomised trial, 1988; 166 people; female intercollegiate athletes and non-athletes: no clear difference. did not report a greater improvement in performance Iron deficiency in female athletes: its prevalence and impact on performancePubMed 3367745
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Magnesium: muscle strength
The studies read are too weak to tell whether Magnesium changes muscle strength. The strongest review read studied hospitalised adults with or at risk for acute alcohol withdrawal. The evidence is very weak.
5 studies counted of 11 read: 3 reviews and 2 trials (65 people in the trials).
1. Systematic review, 2013; 4 studies, 317 people; hospitalised adults with or at risk for acute alcohol withdrawal: unclear: evidence too weak to tell (the review the verdict rests on). no significant increase in handgrip strength Magnesium for alcohol withdrawalPubMed 23740536
2. Meta-analysis, 2017; 14 studies, 542 people; athletes, untrained healthy individuals, elderly, alcoholics: no clear difference. no significant improvements in the supplementation group were observed regarding The effect of magnesium supplementation on muscle fitness: a meta-analysis and systematic reviewPubMed 29637897
3. Meta-analysis, 2000; 12 studies: no clear difference. Strength of evidence favors those studies finding no effect of Mg supplementation, regardless of whether … The effects of magnesium supplementation on exercise performancePubMed 10959930
4. Crossover trial, 2012; 44 people; children and adolescents with cystic fibrosis: improves. MIP and MEP significantly improved only after magnesium administration Oral magnesium supplementation in children with cystic fibrosis improves clinical and functional variables: a double-blind, randomized, placebo-controlled crossover trialPubMed 22648717
5. Crossover trial, 1993; 21 people; mechanically ventilated patients with respiratory failure: no clear difference. There were no significant differences in Pimax (37 +/- 14 vs 42 +/- 20 cm … The lack of effect of routine magnesium administration on respiratory function in mechanically ventilated patientsPubMed 8339645
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Magnesium: endurance performance
The studies read are too weak to tell whether Magnesium changes endurance performance. The evidence is very weak.
4 studies counted of 8 read: 4 trials (95 people in the trials).
1. Randomised trial, 2014; 25 people; professional male volleyball players: improves. significant increases (of up to 3 cm) in countermovement jump Magnesium status and the physical performance of volleyball players: effects of magnesium supplementationPubMed 24015935
2. Crossover trial, 2012; 38 people; healthy, physically active adults: no clear difference. no significant difference between the first Effects of MagPro™ on muscle performancePubMed 22067254
3. Crossover trial, 2001; 32 people; physically active women: no clear difference. performance and recovery indices were not significantly affected The effects of magnesium supplementation on exercise performancePubMed 11252079
4. Randomised trial, 1985; human volunteers and rat quadriceps muscles: no clear difference. neither the exerted force nor the endurance time increased Effects of potassium + magnesium aspartate on muscle metabolism and force development during short intensive static exercisePubMed 3988415
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Panax Ginseng (Korean Ginseng): muscle strength
The studies read are too weak to tell whether Panax Ginseng (Korean Ginseng) changes muscle strength. The evidence is very weak.
4 studies counted of 11 read: 4 trials (170 people in the trials).
1. Crossover trial, 2022; 10 people; male track and field athletes: improves. significantly higher in the Panax ginseng Panax ginseng Supplementation Increases Muscle Recruitment, Attenuates Perceived Effort, and Accelerates Muscle Force Recovery After an Eccentric-Based Exercise in AthletesPubMed 32379240
2. Randomised trial, 2021; 20 people; healthy female college students: improves. Six weeks of Jilin ginseng root supplementation attenuates drop jump-related muscle injury markers in healthy female college studentsPubMed 33507202
3. Randomised trial, 2018; 117 people; sedentary healthy adults: no clear difference. no differences in muscular strength during exercise training Effect of high-dose ginsenoside complex (UG0712) supplementation on physical performance of healthy adults during a 12-week supervised exercise program: A randomized placebo-controlled clinical trialPubMed 29719466
4. Randomised trial, 2016; 23 people; middle-aged and older adults: no clear difference. Panax ginseng and Salvia miltiorrhiza supplementation during eccentric resistance training in middle-aged and older adults: A double-blind randomized control trialPubMed 27912940
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Taurine: endurance performance
The best available review (2025, 23 studies, 308 people) found a small improvement in endurance performance. 3 of the 8 studies read agree; 5 found no clear difference. The evidence is limited.
8 studies counted of 11 read: 2 reviews and 6 trials (77 people in the trials).
1. Meta-analysis, 2025; 23 studies, 308 people: improves (the review the verdict rests on). associated with small-to-moderate improvements in overall performance Does One Shot Work? The Acute Impact of a Single Taurine Dose on Exercise Performance: A Meta-Analytic ReviewPubMed 40852891
2. Meta-analysis, 2018; 10 studies: improves. The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-AnalysisPubMed 29546641
3. Crossover trial, 2025; 16 people; male university students majoring in physical education: improves. time to exhaustion was significantly longer in the medium-dose group Dose-response relationship of taurine on endurance cycling performance under hot and humid conditionsPubMed 41158650
4. Crossover trial, 2025; 11 people; recreationally trained male endurance runners: no clear difference. TTE was not significantly altered (TAU: 1,444.8 ± 88.6 s; PLA: 1,447.6 ± 87.34 s; … Acute Effects of Taurine Supplementation on Maximal Fat Oxidation and FATmax in Recreational Endurance Runners: A Randomized, Placebo-Controlled, Crossover, and Triple-Blinded StudyPubMed 39419489
5. Crossover trial, 2022; 11 people; eleven males cycling in cold conditions: no clear difference. Time to exhaustion was not different between trials Physiological and thermoregulatory effects of oral taurine supplementation on exercise tolerance during forced convective coolingPubMed 33357070
6. Crossover trial, 2016; 17 people; seventeen healthy male volunteers: no clear difference. did not substantially improve high-intensity running performance Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclearPubMed 27109264
7. Crossover trial, 2016; 11 people; trained male cyclists: no clear difference. no effect of TAU (p = 0.731, d = 0.151) on performance The effect of acute taurine ingestion on 4-km time trial performance in trained cyclistsPubMed 27380030
8. Crossover trial, 2010; 11 people; endurance-trained male cyclists: no clear difference. There was no difference in TT performance between any of the 3 trials (1,500 ± … The effect of acute taurine ingestion on endurance performance and metabolism in well-trained cyclistsPubMed 20739720
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Whey Protein: muscle mass
The best available review (2024, 30 studies, 2,105 people) found little or no difference in muscle mass. That review studied older adults aged 60 and older. 2 of the 4 studies read agree; 1 found mixed results, 1 found an improvement. The evidence is moderate.
Possible harm: 1 study read reported a worse result for muscle mass with Whey Protein. One abstract says: "four out of five studies show negative effect of whey protein supplementation at the same dose range (or even higher) compared with control supplementation (-0.49 kg, 95% CI: -0.69, -0.29, I2 = 14%, Z = 4.82, p < 0.001)" Check the studies below, and ask a doctor or pharmacist if this applies to you.
4 studies counted of 8 read: 4 reviews.
1. Meta-analysis, 2024; 30 studies, 2,105 people; older adults aged 60 and older: no clear difference (the review the verdict rests on). ASM significantly improved after WPS consumption Effectiveness of whey protein supplementation on muscle strength and physical performance of older adults: A systematic review and meta-analysis of randomized clinical trialsPubMed 39303495
2. Meta-analysis, 2023; older adults with or without sarcopenia or frailty: mixed results. whey protein supplementation significantly improved LM (SMD = 0.982 Whey Protein Supplementation with or without Vitamin D on Sarcopenia-Related Measures: A Systematic Review and Meta-AnalysisPubMed 37196876
3. Meta-analysis, 2019; 21 studies, 837 people; individuals undergoing resistance training: no clear difference. WP-RT exhibited improved lean mass (MD 0.46 kg Effect of whey protein supplementation during resistance training sessions on body mass and muscular strength: a meta-analysisPubMed 31041966
4. Meta-analysis, 2018; 13 studies, 28 people: improves. WP supplementation increased lean mass (WMD, 0.37 kg Effect of whey protein supplementation on body composition changes in women: a systematic review and meta-analysisPubMed 29688559
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Whey Protein: muscle strength
The studies disagree. A Cochrane review (2012, 12 studies, 13 people) found little or no difference in muscle strength, while 4 of the 8 studies read found an improvement. The evidence is very weak.
8 studies counted of 9 read: 7 reviews and 1 trial (92 people in the trials).
1. Meta-analysis, 2012; 12 studies, 13 people; people with confirmed mitochondrial disease: no clear difference (the review the verdict rests on). no clinical benefit (assessments included the Short Form 36 Treatment for mitochondrial disordersPubMed 22513923
2. Meta-analysis, 2026; 12 studies, 261 people; healthy young adults engaged in resistance training: improves. whey protein significantly improved bench press The Impact of Whey and Soy Protein Supplementation on Resistance Training in Young Adults: A Systematic Review and Meta-AnalysisPubMed 41454445
3. Meta-analysis, 2025; 25 studies, 1,454 people; older adults: improves. increased lower-body muscular strength [SMD: 0.16 Effects of Whey Protein Supplementation on Body Composition, Muscular Strength, and Cardiometabolic Health in Older Adults: A Systematic Review with Pairwise Meta-AnalysisPubMed 41228181
4. Meta-analysis, 2024; 30 studies, 2,105 people; older adults aged 60 and older: no clear difference. no significant positive effect of WPS on HS Effectiveness of whey protein supplementation on muscle strength and physical performance of older adults: A systematic review and meta-analysis of randomized clinical trialsPubMed 39303495
5. Meta-analysis, 2023; 3 studies, 637 people; patients with sarcopenia: mixed results. handgrip strength and SPPB scores in the experimental group significantly improved Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-AnalysisPubMed 36771225
6. Meta-analysis, 2022; 10 studies; postmenopausal women aged 55 years and above: improves. significant positive effect on biceps curl strength Effect of Whey Protein Supplementation in Postmenopausal Women: A Systematic Review and Meta-AnalysisPubMed 36235862
7. Meta-analysis, 2021; 17 studies; older adults aged 60 or older: improves. Effects of Milk Protein in Resistance Training-Induced Lean Mass Gains for Older Adults Aged ≥ 60 y: A Systematic Review and Meta-AnalysisPubMed 34444975
8. Randomised trial, 2026; 92 people; chinese older adults: no clear difference. No intergroup differences were found in changes of ASM or handgrip strength The Impact of Oral Whey Protein and Yeast Protein Supplementation for 6 Months on Skeletal Muscle Mass, Strength, and Function in the Elderly: A Randomized, Controlled, Parallel StudyPubMed 42016236
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.

Key findings

Anaerobic CapacityCreatineImproves (the measure goes up)
Muscle MassSoy ProteinImproves (the measure goes up)
Aerobic Exercise MetricsAshwagandhaImproves (the measure goes up)

The Muscle Size & Strength (Hypertrophy) protocol

2 primary supplements · 4 supporting supplements

Creatine Monohydrate3–5 g daily (loading phase optional: 20 g/day for 5–7 days)
Protein (Whey/Casein)1.6–2.2 g/kg body weight daily (20–40 g per meal)

See the full protocol

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Studies cited

8 studies from PubMed

A Systematic Review with Meta-Analysis of the Effect of Resistance Training on Whole-Body Muscle Growth in Healthy Adult Males.Int J Environ Res Public Health · PMID 32079265
Influence of resistance exercise on lean body mass in aging adults: a meta-analysisMed Sci Sports Exerc · PMID 20543750
Dose-Response Relationships of Resistance Training in Healthy Old Adults: A Systematic Review and Meta-AnalysisSports Med · PMID 26420238
Heavy resistance training at retirement age induces 4-year lasting beneficial effects in muscle strength: a long-term follow-up of an RCT.BMJ Open Sport Exerc Med · PMID 38911477
Muscular adaptations in low- versus high-load resistance training: A meta-analysis.Eur J Sport Sci · PMID 25530577
Comparison of Weightlifting, Traditional Resistance Training and Plyometrics on Strength, Power and Speed: A Systematic Review with Meta-AnalysisSports Med · PMID 35025093
Resistance exercise for muscular strength in older adults: a meta-analysisAgeing Res Rev · PMID 20385254
Effects of Variations in Resistance Training Frequency on Strength Development in Well-Trained Populations and Implications for In-Season Athlete Training: A Systematic Review and Meta-analysis.Sports Med · PMID 33886099