Compound or practice · Supplement
BCAAs
Overhyped and mostly redundant — if you eat enough protein, BCAAs add little.
- Overall grade
- Grade C
- Last revised
- 2
- graded outcomes
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
1 at grade C · 1 at grade D — 2 graded rows
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Fasted-training fatigueEvidence grade C
Minor
Smallmixed
- Muscle growth (adequate protein)Evidence grade D
Redundant
Trivialhigh
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Fasted-training fatigue (grade C); Muscle growth (adequate protein) (grade D).
The evidence in words
What it is
Branched-chain amino acids (leucine, isoleucine, valine) are marketed for muscle growth and recovery.
How it works
Leucine triggers muscle protein synthesis, but without the other essential amino acids, synthesis can't run to completion — the flaw in BCAA-only supplementation.
What the evidence shows
In people eating adequate protein, BCAAs provide little benefit for muscle growth or recovery over a complete protein; whole protein (or EAAs) outperforms them. They can slightly reduce fatigue in fasted training. A largely redundant category for most.
Safety & interactions
Safe; largely a waste of money if protein intake is adequate.
Bottom line
Skip them if you eat enough protein — whole protein or EAAs beat BCAAs. Marginal niche in fasted training only.
Related reading
Entries that share this one's tags or conditions.
- BCAAs for Fasted-training fatigueEvidence grade C — MinorEvidence grade C
- BCAAs for Muscle growth (adequate protein)Evidence grade D — RedundantEvidence grade D
- BCAAs: side effects, safety & interactionsSafe; largely a waste of money if protein intake is adequate.Evidence grade C
- Essential Amino Acids (EAAs)BCAAs done right — all nine essentials, so muscle protein synthesis can actually finish.Evidence grade B
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.