Urolithin A
Summary
Urolithin A at 500–1,000 mg/day for up to 4 months improved muscle endurance and strength measures in older and middle-aged adults (grade C), though primary endpoints such as 6-minute walk and peak power were not met. A 4-week trial found shifts in immune-cell markers (grade C). Trials report no safety signal.
Key facts
- A gut-microbe metabolite of ellagitannins (pomegranate, walnuts, berries); many people make little or none from food[1][8]
- Muscle endurance ↑ (C); leg strength ↑ (C); immune-cell markers (C); 6-minute walk, peak power and running time trial: no significant effect[2][3][4][5][6]
- None set; urolithin A is not an essential nutrient[1]
- Adverse events did not differ from placebo in the 4-month older-adult trial[2]
- 5 graded human outcomes on this page
- October 10, 2026
How it works
ProposedUrolithin A is proposed to work by triggering mitophagy, the recycling of worn-out mitochondria, so that muscle cells replace them with working ones. In humans, 4 weeks at 500–1,000 mg/day changed plasma acylcarnitines and muscle mitochondrial gene expression, which is consistent with this but does not prove it drives the functional results.[1][3]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Muscle | Grade C | Improved | RCT · n = 88 · 2022 | 4 rows |
| Immune | Grade C | Improved | RCT · n = 50 · 2025 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Muscle strength and endurance in middle-aged adults | Improved | Grade C | RCT · n = 88 · 2022 Untrained, overweight adults aged 40–64 Form: urolithin A (Mitopure) · Dose: 500 or 1,000 mg/day · Duration: 4 months Leg muscle strength improved about 12% vs placebo; peak VO2 and 6-minute walk improved, CRP fell. Peak power output, the primary endpoint, did not improve significantly. | 35584623 (opens PubMed)Source [3] |
| Muscle endurance in older adults | Improved | Grade C | RCT · n = 66 · 2022 Adults aged 65–90 in Seattle, mostly women Form: urolithin A · Dose: 1,000 mg/day · Duration: 4 months Hand and leg muscle endurance (contractions to fatigue) improved more than placebo at 2 months; CRP, acylcarnitines and ceramides fell. The primary endpoints, 6-minute walk distance and maximal muscle ATP production, did not differ from placebo. | 35050355 (opens PubMed)Source [2] |
| Immune-cell composition | Improved | Grade C | RCT · n = 50 · 2025 Healthy middle-aged adults Form: urolithin A · Dose: 1,000 mg/day · Duration: 4 weeks Naive-like CD8+ T cells and their fat-burning capacity increased vs placebo; NK-cell and monocyte subsets also shifted. Cytokine changes were secondary outcomes. | 41174221 (opens PubMed)Source [6] |
| Running performance and recovery | No effect | Grade C | RCT · n = 42 · 2025 Highly trained male distance runners at an altitude camp Form: urolithin A · Dose: 1,000 mg/day · Duration: 4 weeks 3,000 m time trial did not improve vs placebo. Perceived exertion and post-exercise creatine kinase (a muscle-damage marker) were lower with urolithin A. | 40839339 (opens PubMed)Source [5] |
| Strength and repetitions in trained men | Mixed | Grade D | RCT · n = 20 · 2024 Resistance-trained male athletes Form: urolithin A · Dose: 1,000 mg/day · Duration: 8 weeks Isometric strength and repetitions to failure improved vs placebo; 1-rep max bench and squat did not differ significantly. | 39487653 (opens PubMed)Source [4] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Urolithin A (direct supplement) | Varies[1] | Detected in plasma at every dose tested in the first-in-human trial in older adults.[1] | Favourable safety profile over 4 weeks; no difference in adverse events vs placebo over 4 months.[1][2] | Muscle endurance and strength, mitochondrial markers |
| Ellagitannin foods (pomegranate, walnuts) as a source | Varies[8] | Urolithin A is only made if the right gut bacteria are present; people fall into producer types (metabotypes A, B or 0), so food intake does not reliably supply it.[7][8] | Food amounts; not a dosing form.[8] | Background dietary exposure |
Studied doses
Doses studied in human trials ranged from 500 to 1,000 mg/day of urolithin A for 4 weeks to 4 months. Most trials used 1,000 mg/day.[1][2][3][6]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Medicines
- No published drug interactions for urolithin A were found in our sources. That is an absence of data, not proof of safety with every medicine.[1][2]
- Pregnancy and breastfeeding
- No trials in pregnancy or breastfeeding in our sources.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Label dose vs clinical doseCompare the mg of urolithin A per serving with the trials: those that found endurance or strength changes used 500–1,000 mg/day for 2–4 months; 4-week trials used 1,000 mg/day.[2][3][6]
- Urolithin A is not pomegranate extractA pomegranate or ellagic acid supplement only becomes urolithin A if your gut bacteria convert it, and many people convert little. Check that the label lists urolithin A itself.[8]
Cost per studied dose, without the sales pitch
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Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
Does urolithin A build muscle?
Not shown. Trials found better muscle endurance and some strength measures in older and middle-aged adults, but not muscle size, and main endpoints such as walking distance and peak power were not met.[2][3]
How much urolithin A was used in studies?
500 to 1,000 mg/day, most often 1,000 mg/day, for 4 weeks to 4 months.[1][2][3][6]
Can I get urolithin A from pomegranate juice?
Only if your gut bacteria make it. People differ in how much urolithin A they produce from pomegranate or walnut polyphenols, and some make almost none.[8]
How long does urolithin A take to work?
Endurance changes were seen at 2 months in older adults and strength changes at 4 months in middle-aged adults. Immune-cell shifts were measured after 4 weeks.[2][3][6]
Sources
- [1]The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans.. Nat Metab, 2019. RCT
- [2]Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial.. JAMA Netw Open, 2022. RCT
- [3]Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults.. Cell Rep Med, 2022. RCT
- [4]Assessment of Urolithin A effects on muscle endurance, strength, inflammation, oxidative stress, and protein metabolism in male athletes with resistance training: an 8-week randomized, double-blind, placebo-controlled study.. J Int Soc Sports Nutr, 2024. RCT
- [5]Evaluating the Impact of Urolithin A Supplementation on Running Performance, Recovery, and Mitochondrial Biomarkers in Highly Trained Male Distance Runners.. Sports Med, 2025. RCT
- [6]Effect of the mitophagy inducer urolithin A on age-related immune decline: a randomized, placebo-controlled trial.. Nat Aging, 2025. RCT
- [7]Urolithins: a Comprehensive Update on their Metabolism, Bioactivity, and Associated Gut Microbiota.. Mol Nutr Food Res, 2022. review
- [8]The gut microbiota metabolism of pomegranate or walnut ellagitannins yields two urolithin-metabotypes that correlate with cardiometabolic risk biomarkers: Comparison between normoweight, overweight-obesity and metabolic syndrome.. Clin Nutr, 2018. observational
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Adversarial review pass: every claim re-checked against the cited abstract (or full text where noted), PMIDs re-verified via NCBI esummary, unsupported label-market statements removed, two evidence rows with unreported pooled n removed. Page set indexable.