Urolithin A for Sarcopenia
Urolithin A is not proven to treat sarcopenia. It shows a plausible mechanism and some encouraging signals in healthy middle-aged and sedentary older adults, but no trial has tested people who actually have sarcopenia, and both pivotal trials missed their main goals.
Why this grade7-layer evidence engine
The grade is weak and disputed because the human evidence, while real, falls short of demonstrating a clinical benefit. The two pivotal double-blind RCTs both failed their pre-specified primary endpoints: in older adults (PMID 35050355, n=66) urolithin A did not significantly improve 6-minute walk distance or muscle ATP production, and in middle-aged adults (PMID 35584623, n=88) it did not improve peak power output. The early Phase I trial (PMID 32694802, n=60) only established safety and a mitochondrial gene signature, with no muscle-strength outcome.
The positive results that marketing tends to highlight, such as roughly 12% greater hamstring strength, higher VO2peak, lower inflammation, and better fatigue resistance, were all secondary endpoints subject to multiple-comparison error. A small trial in trained male athletes (PMID 39487653, n=20) found no significant gain in one-rep-max strength and does not represent a sarcopenia population. Crucially, no trial has enrolled patients with clinically defined sarcopenia, and the one study measuring muscle mass found no increase. Several key trials were funded by the manufacturer (Amazentis), adding a conflict-of-interest concern.
Regulators and clinicians reinforce the cautious read. The US FDA position is purely about food safety (GRAS, FDA has no questions), the EFSA gave only a positive safety opinion at up to 500 mg/day, and the UK application remains under risk assessment and is not authorized; none of these approve any disease or muscle-health claim. Major clinical bodies, including the NIH Office of Dietary Supplements, Mayo Clinic, Cleveland Clinic, and Harvard Health, do not mention urolithin A for sarcopenia at all. The honest takeaway: it may help muscle function, but current evidence cannot support using it to treat sarcopenia, and proven first-line steps remain resistance training and adequate protein.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.613
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
- tier_strict_requirement_check — | B→C 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
- detect_disputes — 偵測到 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status