Supplement
Leucine is an essential amino acid that signals muscle cells to build new protein. People mostly look at it for age-related muscle loss, where it may help overcome the blunted muscle response of aging, and the evidence is moderate across about 600 participants. Other findings are thinner: body fat and liver enzymes showed no clear difference in very limited research on 26 people.
- Updated
- How we grade
- 1 study cited
- Best evidence
- Grade D
- Conditions studied
- 3
- Outcomes
- 15
- Graded outcomes
- 0004
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
Muscle Size Strength
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Body Fat No effect | NoneNo effect | 26 people | ||||
| Liver Enzymes No effect | NoneNo effect | 26 people | ||||
| Rating of Perceived Exertion | Improves (the measure goes up) | 1 study | 26 people | |||
Studies that measured rating of perceived exertion | ||||||
| Muscle Mass | Improves (the measure goes up) | 26 people | ||||
| Power Output | Improves (the measure goes up) | 26 people | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Body Fat No effect | NoneNo effect | 26 people | ||||
| Rating of Perceived Exertion | Improves (the measure goes up) | 1 study | 26 people | |||
Studies that measured rating of perceived exertion | ||||||
| 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 | ||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Body Fat No effect | NoneNo effect | 26 people | ||||
| Rating of Perceived Exertion | Improves (the measure goes up) | 1 study | 26 people | |||
Studies that measured rating of perceived exertion | ||||||
| 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 | ||||
Key findings
- Body Fat
- Liver Enzymes
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- Grade D
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Studies cited
1 study from PubMed