Effects of Urolithin A supplementation on muscle health outcomes in humans from randomized controlled trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 42559151 · doi:10.3389/fnut.2026.1834344
What was done
Systematic review and meta-analysis of randomized controlled trials identified across PubMed, Embase, Web of Science, and Scopus through December 2025 comparing oral Urolithin A against placebo for muscle performance and biochemical or mitochondrial biomarkers. Risk of bias was assessed with the Cochrane RoB 2 tool and certainty was evaluated using GRADE. Quantitative pooling using inverse-variance weighting was feasible only for the 6-minute walk test (6MWT), with remaining outcomes synthesized narratively.
What was found
Five RCTs with a total of 236 participants were included. Meta-analysis for the 6MWT across two trials (k = 2) showed a pooled mean difference of +17.03 m (95% CI: -5.33 to 39.40 m; p = 0.135; I² = 0%), with a sensitivity analysis yielding +18.80 m (95% CI: -3.24 to 40.85 m; p = 0.095), graded as low certainty evidence. Other endpoints (muscle strength, endurance, aerobic capacity, and mitochondrial biomarkers) were heterogeneous in populations, dosing, and assessment modalities, precluding quantitative pooling.
Why it matters
Despite interest in Urolithin A for muscle and mitochondrial health, current randomized human trial evidence remains small and statistically inconclusive for functional performance.
Limits
The total evidence base comprises only five small, short-term trials with clinically heterogeneous populations and varied dosing regimens. Meta-analysis was restricted to a single functional test across two studies, leaving strength, endurance, and biomarker findings as exploratory narrative observations.
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