Leucine

Leucine is a branched-chain amino acid (BCAA) and potent nutrient-based signal to activate protein synthesis.

Quick Answer

What it is

Leucine is a branched-chain amino acid (BCAA) and potent nutrient-based signal to activate protein synthesis.

Key findings

  • Grade D: Body Fat
  • Grade D: Liver Enzymes
  • Grade N/A: Muscle Mass

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts: Leucine

Quick Facts: Leucine

  • Best Evidence:Grade D
  • Conditions Studied:2
  • Research Outcomes:15
  • Key Effect:General Athletic Performance
Outcomes by grade:
A0
B0
C0
D4
2 conditions · 15 outcomes

Detailed Outcomes

|
D
Body Fat
No effect
1 study
none
D
Liver Enzymes
No effect
1 study
none
?
Muscle Mass
1 study
Improves
?
Power Output
1 study
Improves
?
Rating of Perceived Exertion
Improves
D
Body Fat
No effect
1 study
none
?
Liver Enzymes
1 study
Worsens
?
Muscle Mass
1 study
Improves
?
Power Output
1 study
Improves
?
Rating of Perceived Exertion
Improves
D
Body Fat
No effect
1 study
none
?
Liver Enzymes
1 study
Worsens
?
Muscle Mass
1 study
Improves
?
Power Output
1 study
Improves
?
Rating of Perceived Exertion
Improves

Related Supplements

Whey Protein

3 shared conditions · 197 outcomes

Whey protein is one of the two high-quality proteins derived from cow’s milk (casein being the other). Its high digestibility, quick absorption, and well-researched benefits for muscle gain and cardiometabolic health make it a popular protein supplement among athletes and older adults.

Vitamin D

3 shared conditions · 308 outcomes

Vitamin D is a fat-soluble vitamin that our skin synthesizes when exposed to the sun. It benefits us in many ways, from bone health to mood.

Velvet Antler

3 shared conditions · 63 outcomes

Velvet Antler (usually from deer) is crushed antler that is orally consumed for preventative health purposes. Hailing from Traditional Chinese Medicine, velvet antler does not appear to influence hormones and is currently unsupported for muscle repair (although it may aid skin regeneration rates).

Ursolic Acid

3 shared conditions · 25 outcomes

Ursolic Acid is a molecule found in apple peels, and in the Ayurveda herb known as Holy Basil. No human interventions exist right now, but ursolic acid appears to be a promising body recomposition agent; able to increase muscle mass and decrease fat mass. May be anti-fertility, however.

Tribulus Terrestris

3 shared conditions · 100 outcomes

Tribulus terrestris is a plant whose root and fruits are used in Ayurvedic medicine for male virility and general vitality, respectively. It is also used in Traditional Chinese Medicine. It appears to reduce symptoms of sexual dysfunction (but not improve testosterone levels) in men and women and might improve metabolic health as well.

Tongkat Ali

3 shared conditions · 112 outcomes

Tongkat Ali is a Southeast Asian herb traditionally used as an aphrodisiac and adaptogen. B-grade evidence for erectile function (small effect). C-grade evidence for cortisol reduction. IMPORTANT: Despite heavy marketing as a 'testosterone booster', evidence for testosterone increases in healthy men with normal testosterone is weak and inconsistent. Effects on testosterone appear limited to men with clinically low levels. Most studies have small sample sizes and methodological limitations. May have genuine adaptogenic effects on stress/cortisol.

Terminalia Arjuna

3 shared conditions · 17 outcomes

Arjuna is typically made from the bark of the tree Terminalia arjuna, a large tree common throughout India. It has most often been studied for cardiovascular disease, where it has improved heart failure in some studies. Arjuna has inconsistently improved other cardiac outcomes such as blood pressure.

Spirulina

3 shared conditions · 304 outcomes

Spirulina, commonly known as “blue-green algae”, is a nontoxic cyanobacterium that is rich in various nutrients and bioactive pigments and polyphenols. Spirulina contains many antioxidant compounds and could have beneficial cardiometabolic effects.