Back to collection
HMB
Performance
HMB (β-Hydroxy β-Methylbutyrate)
Leucine metabolite; may reduce muscle protein breakdown.
What it is
HMB is a metabolite of the branched-chain amino acid leucine. It's studied for anti-catabolic effects, particularly in trained individuals and older adults.
How it works
Inhibits the ubiquitin-proteasome proteolytic pathway; supports mTOR signaling and muscle protein synthesis.
What the evidence says
Moderate evidence for reducing muscle breakdown in untrained/elderly; less clear benefit in well-trained athletes.
Safety Notes
- Most beneficial for untrained individuals or older adults at risk of muscle loss. Free acid form absorbs faster.
- Use caution with: severe kidney disease (caution).
- statins: Both affect cholesterol pathways; theoretical interaction. Monitor.
Timing With Other Supplements
- Creatine Monohydrate: Complementary; often stacked together for muscle support.