HMB is a metabolite of the essential amino acid leucine. Its primary proposed mechanism involves simultaneously stimulating muscle protein synthesis via the mTOR pathway and inhibiting muscle protein breakdown (proteolysis). For healthspan, its relevance is focused on combating sarcopenia (age-related muscle loss), a key driver of frailty, metabolic decline, and reduced functional independence in older adults.
Verdict
A safe, targeted supplement for potentially mitigating age-related muscle loss.
HEALTHSPAN IMPACT
Moderate
RISK LEVEL
Low
EVIDENCE GRADE
A
MONTHLY COST
$15 - $35
Protocol
- Take 3 grams daily, often split into three 1-gram doses with meals.
Flags
- Evidence for benefit is strongest in untrained, elderly, or clinical populations.
- May be less effective for individuals already consuming high-protein diets and resistance training.