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Dr. Grey AI

Supplement

HMB

HMB is a natural byproduct of leucine, an amino acid, and it appears to slow the breakdown of muscle protein in the body. People mostly look at it for muscle size and strength, and the evidence is moderate, though anaerobic capacity in 28 people and body fat in people with sarcopenia showed no clear difference. Those results are very limited, so they say little about muscle gain itself.

Sources: PMID 23286834; PMID 39071082

Best evidence
Grade C
Conditions studied
12
Outcomes
132
Graded outcomes
00211

Evidence by condition

  • Strong
  • Moderate
  • Limited
  • Very limited

12 conditions

Metabolic Health

Metabolic Health: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Blood glucose

Small Improvement

Improves (the measure goes down)Small effect8 people
Muscle MassImproves (the measure goes up)8 studies8 people

Studies that measured muscle mass

Body FatImproves (the measure goes down)1 study8 people

Studies that measured body fat

High-density lipoprotein (HDL)Improves (the measure goes up)1 study421 people

Studies that measured high-density lipoprotein (hdl)

Low-density lipoprotein (LDL)Improves (the measure goes down)421 people
Oxygen UptakeImproves (the measure goes up)8 people
Total cholesterolImproves (the measure goes down)421 people
TriglyceridesImproves (the measure goes down)421 people
UreaImproves (the measure goes up)8 people

Martial Arts Performance

Martial Arts Performance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Blood glucose

Small Improvement

Improves (the measure goes down)Small effect8 people
Muscle MassImproves (the measure goes up)8 studies8 people

Studies that measured muscle mass

Power OutputImproves (the measure goes up)2 studies8 people

Studies that measured power output

Body FatImproves (the measure goes down)1 study8 people

Studies that measured body fat

High-density lipoprotein (HDL)Improves (the measure goes up)1 study8 people

Studies that measured high-density lipoprotein (hdl)

Low-density lipoprotein (LDL)Improves (the measure goes down)8 people
Oxygen UptakeImproves (the measure goes up)8 people
Total cholesterolImproves (the measure goes down)8 people
TriglyceridesImproves (the measure goes down)8 people
UreaImproves (the measure goes up)8 people

Muscle Size Strength

  • Body Fat
  • Anaerobic Capacity
  • Muscle Mass: improves
Muscle Size Strength: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Body Fat

No effect

NoneNo effect1 study448 people

Studies that measured body fat

Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies737 people

Studies that measured muscle mass

Muscle SorenessImproves (the measure goes down)2 studies26 people

Studies that measured muscle soreness

Power OutputImproves (the measure goes up)2 studies209 people

Studies that measured power output

High-density lipoprotein (HDL)Improves (the measure goes up)1 study28 people
Liver EnzymesChanges; see studies1 study68 people
Muscle DamageChanges; see studies1 study387 people
StrengthImproves (the measure goes up)1 study1,935 people
Bone Mineral DensityImproves (the measure goes up)68 people
CortisolImproves (the measure goes down)26 people
Fatigue SymptomsImproves (the measure goes down)63 people
Food IntakeChanges; see studies125 people
Low-density lipoprotein (LDL)Improves (the measure goes down)28 people
TestosteroneImproves (the measure goes up)26 people
Total cholesterolImproves (the measure goes down)28 people
Training VolumeImproves (the measure goes up)63 people
WeightImproves (the measure goes down)193 people

Weight Loss & Maintenance

  • Body Fat
  • Muscle Mass: improves
  • Liver Enzymes: changes; see studies
Weight Loss & Maintenance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Body Fat

No effect

NoneNo effect1 study77 people

Studies that measured body fat

Muscle MassImproves (the measure goes up)8 studies77 people

Studies that measured muscle mass

Liver EnzymesChanges; see studies1 study40 people

Studies that measured liver enzymes

Muscle DamageChanges; see studies1 study37 people

Studies that measured muscle damage

Bone Mineral DensityImproves (the measure goes up)40 people
Fatigue SymptomsImproves (the measure goes down)37 people
Food IntakeChanges; see studies77 people

Sarcopenia

  • Body Fat
  • Fat-free mass (FFM): improves
Sarcopenia: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Body Fat

No effect

NoneNo effect1 study638 people

Studies that measured body fat

Fat-free mass (FFM)Improves (the measure goes up)273 people

General Athletic Performance

  • Anaerobic Capacity
  • Muscle Mass: improves
  • Muscle Soreness: improves
General Athletic Performance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies198 people

Studies that measured muscle mass

Muscle SorenessImproves (the measure goes down)2 studies26 people

Studies that measured muscle soreness

Power OutputImproves (the measure goes up)2 studies275 people

Studies that measured power output

Body FatImproves (the measure goes down)1 study169 people

Studies that measured body fat

High-density lipoprotein (HDL)Improves (the measure goes up)1 study36 people
Liver EnzymesChanges; see studies1 study68 people
Muscle DamageChanges; see studies1 study387 people
Blood glucoseImproves (the measure goes down)8 people
Bone Mineral DensityImproves (the measure goes up)68 people
CortisolImproves (the measure goes down)55 people
Fatigue SymptomsImproves (the measure goes down)63 people
Food IntakeChanges; see studies125 people
Growth HormoneImproves (the measure goes up)29 people
IGF-1Improves (the measure goes up)29 people
Interleukin 6Improves (the measure goes down)29 people
Low-density lipoprotein (LDL)Improves (the measure goes down)36 people
Oxygen UptakeImproves (the measure goes up)8 people
TestosteroneImproves (the measure goes up)55 people
Total cholesterolImproves (the measure goes down)36 people
Training VolumeImproves (the measure goes up)63 people
TriglyceridesImproves (the measure goes down)8 people
UreaImproves (the measure goes up)8 people

Body Composition

  • Anaerobic Capacity
  • Muscle Mass: improves
  • Power Output: improves
Body Composition: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies152 people

Studies that measured muscle mass

Power OutputImproves (the measure goes up)2 studies203 people

Studies that measured power output

Body FatImproves (the measure goes down)1 study123 people

Studies that measured body fat

Blood glucoseImproves (the measure goes down)8 people
Bone Mineral DensityImproves (the measure goes up)28 people
CortisolImproves (the measure goes down)29 people
Food IntakeChanges; see studies22 people
Growth HormoneImproves (the measure goes up)29 people
IGF-1Improves (the measure goes up)29 people
Interleukin 6Improves (the measure goes down)29 people
Low-density lipoprotein (LDL)Improves (the measure goes down)36 people
Oxygen UptakeImproves (the measure goes up)8 people
TestosteroneImproves (the measure goes up)29 people
UreaImproves (the measure goes up)8 people

Muscle Recovery

  • C-Reactive Protein (CRP)
  • Muscle Soreness: improves
  • Power Output: improves
Muscle Recovery: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
C-Reactive Protein (CRP)

No effect

NoneNo effect20 people
Muscle SorenessImproves (the measure goes down)2 studies40 people

Studies that measured muscle soreness

Power OutputImproves (the measure goes up)2 studies46 people

Studies that measured power output

Muscle DamageChanges; see studies1 study370 people

Studies that measured muscle damage

CortisolImproves (the measure goes down)46 people
Fatigue SymptomsImproves (the measure goes down)26 people
Range of MotionImproves (the measure goes up)14 people
TestosteroneImproves (the measure goes up)46 people
Training VolumeImproves (the measure goes up)46 people

Football Performance

  • Anaerobic Capacity
  • Muscle Mass: improves
  • Muscle Soreness: improves
Football Performance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies28 people

Studies that measured muscle mass

Muscle SorenessImproves (the measure goes down)2 studies26 people

Studies that measured muscle soreness

Power OutputImproves (the measure goes up)2 studies54 people

Studies that measured power output

Body FatImproves (the measure goes down)1 study28 people

Studies that measured body fat

Muscle DamageChanges; see studies1 study26 people
CortisolImproves (the measure goes down)26 people
Fatigue SymptomsImproves (the measure goes down)26 people
TestosteroneImproves (the measure goes up)26 people
Training VolumeImproves (the measure goes up)26 people

Running Performance

  • Anaerobic Capacity
  • Muscle Mass: improves
  • Power Output: improves
Running Performance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies28 people

Studies that measured muscle mass

Power OutputImproves (the measure goes up)2 studies28 people

Studies that measured power output

Body FatImproves (the measure goes down)1 study28 people

Studies that measured body fat

Volleyball Performance

  • Cortisol
  • Muscle Mass: improves
  • Power Output: improves
Volleyball Performance: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Cortisol

No effect

NoneNo effect29 people
Muscle MassImproves (the measure goes up)8 studies29 people

Studies that measured muscle mass

Power OutputImproves (the measure goes up)2 studies58 people

Studies that measured power output

Growth HormoneImproves (the measure goes up)29 people
IGF-1Improves (the measure goes up)29 people
Interleukin 6Improves (the measure goes down)29 people
TestosteroneImproves (the measure goes up)29 people

Muscle Size & Strength

  • Anaerobic Capacity
  • Muscle Mass: improves
  • Muscle Soreness: changes; see studies
Muscle Size & Strength: outcomes studied for HMB
GradeOutcomeEffectSizeStudiesPeopleStudies list
Anaerobic Capacity

No effect

NoneNo effect28 people
Muscle MassImproves (the measure goes up)8 studies737 people

Studies that measured muscle mass

Muscle SorenessChanges; see studies2 studies26 people

Studies that measured muscle soreness

Power OutputImproves (the measure goes up)2 studies187 people

Studies that measured power output

Body FatChanges; see studies1 study448 people

Studies that measured body fat

High-density lipoprotein (HDL)Improves (the measure goes up)1 study28 people
Liver EnzymesChanges; see studies1 study68 people
Muscle DamageChanges; see studies1 study387 people
StrengthImproves (the measure goes up)1 study1,935 people
Bone Mineral DensityImproves (the measure goes up)68 people
CortisolChanges; see studies26 people
Fatigue SymptomsChanges; see studies63 people
Food IntakeChanges; see studies125 people
Low-density lipoprotein (LDL)Changes; see studies28 people
TestosteroneImproves (the measure goes up)26 people
Total cholesterolChanges; see studies28 people
Training VolumeImproves (the measure goes up)63 people
WeightChanges; see studies193 people

Key findings

  • Blood glucoseMetabolic HealthImproves (the measure goes down)
  • Body Fat
  • Anaerobic Capacity

Shop HMB

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  • Grade C

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Studies cited

29 studies from PubMed

  1. The Role of HMB Supplementation in Enhancing the Effects of Resistance Training in Older Adults: A Systematic Review and Meta-Analysis on Muscle Quality, Body Composition, and Physical Function.Nutrients, 2025 · PMID 41305674
  2. Effects of β-hydroxy-β-methylbutyrate (HMB) supplementation on lipid profile in adults: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials.Front Nutr, 2024 · PMID 39385778
  3. HMB Supplementation in Elderly Populations: A Systematic Review and Meta-AnalysisClin Nutr, 2019 · PMID 30092696
  4. Efficacy of HMB in Hospitalized Older Patients: A Randomized Controlled TrialNutr Clin Pract, 2019 · PMID 30541308
  5. HMB for Preservation of Muscle Mass in Older Adults: A Systematic ReviewJ Nutr Health Aging, 2018 · PMID 29478892
  6. Effects of HMB on Exercise-Induced Muscle Damage: A Meta-AnalysisJ Am Coll Nutr, 2018 · PMID 29129718
  7. Effects of HMB on Skeletal Muscle in Catabolic ConditionsNutrients, 2018 · PMID 29619588
  8. International Society of Sports Nutrition Position Stand: Beta-Hydroxy-Beta-Methylbutyrate (HMB)J Int Soc Sports Nutr, 2017 · PMID 28852372
  9. Beta-Hydroxy-Beta-Methylbutyrate and Muscle Protein Synthesis: A ReviewCurr Opin Clin Nutr Metab Care, 2017 · PMID 28615903
  10. HMB for Prevention of Sarcopenia in Older Adults: Clinical EvidenceClin Nutr, 2017 · PMID 28557540
  11. HMB and Resistance Training: A Comprehensive ReviewSports Med, 2017 · PMID 29108901
  12. Effects of HMB Supplementation on Strength and Muscle Mass: A Meta-AnalysisJ Strength Cond Res, 2016 · PMID 27164507
  13. Beta-Hydroxy-Beta-Methylbutyrate Free Acid and Muscle Protein AnabolismInt J Sport Nutr Exerc Metab, 2016 · PMID 27710596
  14. Safety and Tolerability of Long-Term HMB SupplementationJ Am Coll Nutr, 2016 · PMID 27575826
  15. Body composition in 70-year-old adults responds to dietary beta-hydroxy-beta-methylbutyrate similarly to that of young adultsJ Nutr · PMID 11435528
  16. The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled studyEur J Appl Physiol · PMID 21327797
  17. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained menInt J Sport Nutr Exerc Metab · PMID 11599506
  18. Effects of nine weeks of beta-hydroxy-beta- methylbutyrate supplementation on strength and body composition in resistance trained menJ Strength Cond Res · PMID 19387396
  19. Effects of beta-hydroxy beta-methylbutyrate on power performance and indices of muscle damage and stress during high-intensity trainingJ Strength Cond Res · PMID 15574078
  20. Effects of calcium beta-hydroxy-beta-methylbutyrate (HMB) supplementation during resistance-training on markers of catabolism, body composition and strengthInt J Sports Med · PMID 10606212
  21. Beta-hydroxy-beta-methylbutyrate ingestion, Part I: effects on strength and fat free massMed Sci Sports Exerc · PMID 11128859
  22. The Effects of Beta-Hydroxy-Beta-Methylbutyrate Supplementation on Recovery Following Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis.J Am Coll Nutr · PMID 29676656
  23. Effects of oral supplementation of β -hydroxy-β -methylbutyrate on muscle mass and strength in individuals over the age of 50: a meta-analysis.Front Nutr · PMID 40248035
  24. Effects of oral administration of β-hydroxy β-methylbutyrate on lean body mass in older adults: a systematic review and meta-analysisEur Geriatr Med · PMID 33034021
  25. Supplementation with the Leucine Metabolite β-hydroxy-β-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-AnalysisNutrients · PMID 32456217
  26. Effects of beta-hydroxy-beta-methylbutyrate supplementation on strength and body composition in trained and competitive athletes: A meta-analysis of randomized controlled trialsJ Sci Med Sport · PMID 29249685
  27. Exercise-induced muscle damage is not attenuated by beta-hydroxy-beta-methylbutyrate and alpha-ketoisocaproic acid supplementationJ Strength Cond Res · PMID 20072045
  28. β-Hydroxy-β-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained menBr J Nutr · PMID 23286834
  29. The effects of β-hydroxy-β-methylbutyrate or HMB-rich nutritional supplements on sarcopenia patients: a systematic review and meta-analysis.Front Med · PMID 39071082

Protocols that include HMB