Benefits
Muscle Strength in Middle-Aged Adults
In a 4-month trial in 88 untrained, overweight adults aged 40 to 64, hamstring strength rose about 10 to 12% on urolithin A at 500 or 1,000 mg a day while it fell on placebo, a significant difference. The main outcome, peak power on a cycling test, did not improve. The maker sponsored the trial and employed most of its authors.
Muscle Endurance in Older Adults
In a 4-month trial in 66 adults aged 65 to 90, 1,000 mg a day increased how many hand and leg muscle contractions people could do before fatigue, compared with placebo. The main outcomes, 6-minute walk distance and muscle energy (ATP) production, did not differ from placebo.
Mitophagy and Mitochondrial Markers in Aging Adults
In laboratory and animal research, urolithin A switches on mitophagy, the recycling of worn-out mitochondria. In older adults, 4 weeks at 500 or 1,000 mg a day changed muscle mitochondrial gene activity and blood acylcarnitines, and a 4-month trial in middle-aged adults raised muscle proteins linked to mitophagy. These are markers, not proven health outcomes.
Exercise Performance and Recovery in Athletes
In 42 highly trained male runners, 1,000 mg a day for 4 weeks did not improve 3,000 m race times, but lowered perceived effort and a blood marker of muscle damage after running. Small trials in 20 resistance-trained men and 20 young soccer players reported gains in some strength, endurance or jump tests. A pooled analysis judged muscle findings exploratory.
Age-Related Immune Cell Markers
In a 4-week trial in 50 healthy middle-aged adults, 1,000 mg a day increased naive-like CD8 T cells and their capacity to burn fat for energy, and shifted some other immune cell types, compared with placebo. The maker funded the trial. These are laboratory immune measures, not tested health outcomes.
Urolithin A Production Varies Between People
Gut bacteria make urolithin A from ellagitannins in pomegranates, berries and nuts, but in a maker-sponsored study only 12% of healthy adults had detectable levels at the start, and about 40% converted pomegranate juice into it. A 500 mg dose of urolithin A gave more than six times the exposure of the juice.
Mechanism of action
Mitophagy Activation
In laboratory and animal research, urolithin A stimulates mitophagy, the process that clears damaged mitochondria, and improved muscle health in old animals. In people, trials measured related markers: changes in muscle mitochondrial gene activity, more muscle proteins linked to mitophagy and mitochondrial metabolism, and lower blood acylcarnitines. In elite runners, mitophagy markers rose but not significantly.
Clinical trials
Randomized, double-blind, placebo-controlled trial (ATLAS) of Mitopure urolithin A at 500 mg or 1,000 mg a day versus placebo for 4 months. Sponsored by the maker, Amazentis, which employed most authors. (Singh et al. 2022, Cell Rep Med)
88 untrained, overweight adults aged 40 to 64 with low aerobic fitness.
The primary outcome, peak power output, did not differ from placebo. Hamstring peak torque rose 12% (500 mg) and 9.8% (1,000 mg) while it fell 9.8% on placebo, significant differences versus placebo. At 1,000 mg, peak VO2 and 6-minute walk distance (+33 m) improved within the group, but the differences from placebo were not statistically significant. Plasma acylcarnitines fell at 500 mg and CRP fell with urolithin A, and adverse events were reported by 17 participants on placebo and 13 and 15 on the two doses.
Double-blind, placebo-controlled randomized trial in Seattle: 1,000 mg urolithin A or placebo daily for 4 months. Several authors were Amazentis employees or board members. (Liu et al. 2022, JAMA Netw Open)
66 adults aged 65 to 90 (mean 71.7 years, 76% women, all White).
The primary outcomes did not differ from placebo: 6-minute walk distance rose 60.8 m on urolithin A and 42.5 m on placebo, and maximal muscle ATP production did not change. Muscle endurance, counted as contractions until fatigue in a hand and a leg muscle, improved versus placebo, and plasma acylcarnitines, ceramides and CRP fell. Adverse events did not differ between groups.
Randomized, double-blind, placebo-controlled parallel trial during a 4-week altitude training camp: 1,000 mg urolithin A or placebo daily. Funded by Amazentis, which employed three authors. (Whitfield et al. 2025, Sports Med)
42 highly trained male distance runners (22 urolithin A, 20 placebo); 22 completed a 3,000 m time trial and 20 gave muscle biopsies.
3,000 m time-trial performance did not improve in either group, and the rise in VO2max did not differ significantly from placebo. After the time trial, urolithin A lowered ratings of perceived exertion and creatine kinase, a blood marker of muscle damage. Mitophagy markers showed a medium but non-significant rise, with no change in mitochondrial function.
Randomized, double-blind, placebo-controlled trial: 1,000 mg urolithin A or placebo daily for 4 weeks. Funded by Amazentis, which supplied the product. (Denk et al. 2025, Nat Aging)
50 healthy middle-aged adults.
For the primary outcomes, naive-like CD8 T cells rose by 0.50 percentage points versus placebo (P=0.0437) and their fatty acid oxidation capacity by 14.72 points (P=0.0061). Secondary measures showed more mitochondrial biogenesis in CD8 cells, shifts in NK cells and monocytes, and better T cell TNF release and monocyte bacterial uptake. These are laboratory immune measures over 4 weeks.
Systematic review and meta-analysis of randomized placebo-controlled trials published up to December 2025, with risk of bias and GRADE certainty ratings. (Dao et al. 2026, Front Nutr)
5 small randomized trials with 236 participants in total.
Only the 6-minute walk test could be pooled (2 trials): +17.0 m versus placebo, not statistically significant (95% CI -5.3 to 39.4 m, p=0.135), with low certainty. The authors judged strength, endurance and mitochondrial findings to be exploratory signals rather than reproducible effects and called for larger, longer trials.