Urolithin A Benefits: What Small Trials Show About Muscle

Quick answer

Urolithin A benefits, in short: Urolithin A is a compound made by bacteria in your gut when they digest certain plant chemicals found in pomegranates, berries and walnuts. In animals it helped muscles and extended lifespan in a roundworm [1]. In people, the human trials so far are small, short, and several were funded by the company that makes the main product. They show shifts in blood and muscle markers and some signs of better muscle endurance, but the main goals of those trials were often not met [4][5][8]. We rate the evidence D: early and promising, but not proven. It looked safe in the short trials done so far [3][4].

What is urolithin A?

Your cells have tiny “power stations” called mitochondria. Urolithin A is thought to nudge cells to clear out worn-out mitochondria so they can be replaced, a process called mitophagy. That is the theory behind the hype. Not everyone makes urolithin A from food: the gut bacteria involved differ a lot from person to person [2]. The supplements used in research contain a lab-made version, not pomegranate extract.

Urolithin A benefits: what might it help with?

Possible benefit	Rating	In plain words
Blood and muscle markers of mitochondrial health	Promising	Markers moved in the expected direction in several small trials [3][4][5]. These are lab markers, not health results
Muscle strength and endurance (middle-aged and older adults)	Mixed	Some measures improved, but the main goals were missed in two trials [4][5]. A 2026 review called the evidence exploratory [8]
Walking distance (6-minute walk)	Early	A pooled result was positive but not statistically convincing, and rated low-certainty [8]
Immune cells	Early	A 4-week trial in 50 adults found changes in immune cell types [6]. Whether that helps health is unknown
Athletic performance (trained runners)	No clear benefit	A 3000 m time trial did not improve significantly [7]
Artery function (adults with obesity)	No clear benefit	No significant change in flow-mediated dilation after 4 weeks in a 50-person trial [12]
Living longer	Early (animal or lab only)	Lifespan rose in roundworms and muscle function improved in rodents [1]. No human trial has tested this

Ratings describe how good the research is, not a promise that it will work for you.

What the research says

• Animals. Urolithin A triggered the clean-up of worn mitochondria and extended lifespan in the roundworm C. elegans, and improved muscle function in rodents [1]. PubMed
• First human safety trial. In healthy, inactive older adults, urolithin A was well tolerated, entered the bloodstream, and changed muscle gene activity and blood markers after 4 weeks at 500 mg and 1,000 mg a day [3]. PubMed
• Older adults, muscle. In 66 adults aged 65 to 90, 1,000 mg a day for 4 months improved muscle endurance at 2 months, with lower levels of some blood inflammation and fat-burning markers. The main goals (walking distance and muscle energy production) showed no significant difference from placebo, and adverse events were similar between groups [4]. PubMed
• Middle-aged adults. In a company-funded 4-month trial, muscle strength rose about 12% on urolithin A, but the main goal (peak power output) did not improve significantly [5]. PubMed
• Immune system. In 50 healthy middle-aged adults, 4 weeks of 1,000 mg a day changed the make-up and activity of some immune cells compared with placebo. The study was funded by the product’s maker [6]. PubMed
• Runners. In 42 trained runners, 4 weeks at altitude on 1,000 mg a day did not significantly improve a 3000 m time trial, although perceived effort and a muscle-damage marker were lower [7]. PubMed
• Adults with obesity (2026). In 50 adults aged 40 to 64 with a BMI of 30 or more, 1,000 mg a day for 4 weeks did not significantly change the main measure (how well an artery widens, called flow-mediated dilation) or other measures of blood vessel function. Brain blood-flow responses during a task were greater on urolithin A than placebo, while task performance was unchanged. It was well tolerated and the authors say the brain finding warrants further investigation. The abstract doesn’t say who funded it [12].
• Overall. A 2026 review found only five small, short randomized trials (236 people in total) and called the findings hypothesis-generating, not proof it works [8]. PubMed

Amounts and how people take it

These are amounts used in studies, not recommendations.

• Form: a lab-made (synthetic) urolithin A powder or capsule.
• Amounts in trials: 500 mg or 1,000 mg a day, taken for 4 weeks to 4 months [3][4][5][6][7].
• Not the same as pomegranate: juice or extract contains the plant precursors, and whether you turn them into urolithin A depends on your gut bacteria [2].

Side effects, interactions and who should check first

What trials found

Adverse events did not differ from placebo in the trials we read, and the first-in-human study reported a favorable safety profile at up to 1,000 mg a day [3][4]. The longest trial lasted 4 months, so long-term safety is unknown.

Who should check with a doctor or pharmacist first

Check with a doctor or pharmacist first if you:

• take any regular medicine. We did not find human studies testing urolithin A alongside medicines, so interactions are unknown rather than ruled out
• are pregnant, breastfeeding or trying to conceive, or are under 18. We found no human safety data for these groups
• have a long-term health condition, or have had cancer. The human trials were short and enrolled healthy volunteers.

Where can I buy it?

Availability varies by country; not authorized for sale in the UK or EU yet [9][10][11].

We don’t link to any urolithin A products.

FAQ

What are the benefits of urolithin A?

In animals it helped muscles and extended lifespan in a roundworm [1]. In people, small, short trials show shifts in blood and muscle markers and some signs of better muscle endurance, but the main goals were often not met [4][5][8]. A 2026 trial in adults with obesity found no significant change in artery function. We rate the evidence D.

Can you buy urolithin A?

Availability varies by country; urolithin A is not authorized for sale in the UK or EU yet [9][10][11]. We haven’t verified its US availability and we don’t link to any urolithin A products. If you are thinking of trying it, read the label carefully and ask a doctor or pharmacist first, especially if you take any medicine.

Is urolithin A safe?

Adverse events did not differ from placebo in the trials we read, and the first-in-human study reported a favorable safety profile at up to 1,000 mg a day [3][4]. The longest trial lasted 4 months, so long-term safety is unknown, and we found no studies of urolithin A with medicines.

Is pomegranate the same as urolithin A?

No. Pomegranate juice or extract contains the plant precursors, and whether you turn them into urolithin A depends on your gut bacteria, which differ a lot from person to person [2]. The supplements used in research contain a lab-made version of urolithin A, not pomegranate extract.

Related pages

• NMN: another longevity supplement, information only
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• All supplements A-Z

Talk to your doctor

This page is for general information and is not medical advice. Speak to a doctor or pharmacist before starting any supplement, especially if you are pregnant or breastfeeding, take any medicine, or have a health condition.

References

We cite only studies and official pages we checked against PubMed, the publisher or the agency’s own site. The A to E evidence grades are explained in our editorial policy. See also our medical disclaimer and affiliate disclosure.

1. Ryu D, Mouchiroud L, Andreux PA, Katsyuba E, et al. Urolithin A induces mitophagy and prolongs lifespan in C. elegans and increases muscle function in rodents. Nat Med. 2016. PubMed · DOI
2. Tomás-Barberán FA, González-Sarrías A, García-Villalba R, Núñez-Sánchez MA, et al. Urolithins, the rescue of “old” metabolites to understand a “new” concept: Metabotypes as a nexus among phenolic metabolism, microbiota dysbiosis, and host health status. Mol Nutr Food Res. 2017. PubMed · DOI
3. Andreux PA, Blanco-Bose W, Ryu D, Burdet F, et al. The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans. Nat Metab. 2019. PubMed · DOI
4. Liu S, D’Amico D, Shankland E, Bhayana S, et al. Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial. JAMA Netw Open. 2022. PubMed · DOI
5. Singh A, D’Amico D, Andreux PA, Fouassier AM, et al. Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults. Cell Rep Med. 2022. PubMed · DOI
6. Denk D, Singh A, Kasler HG, D’Amico D, et al. Effect of the mitophagy inducer urolithin A on age-related immune decline: a randomized, placebo-controlled trial. Nat Aging. 2025. PubMed · DOI
7. Whitfield J, McKay AKA, Tee N, McCormick R, et al. Evaluating the Impact of Urolithin A Supplementation on Running Performance, Recovery, and Mitochondrial Biomarkers in Highly Trained Male Distance Runners. Sports Med. 2025. PubMed · DOI
8. Dao T, Nguyen TT, Gariani K, Kim HJ, et al. Effects of Urolithin A supplementation on muscle health outcomes in humans from randomized controlled trials. Front Nutr. 2026. PubMed · DOI
9. Food Standards Agency. Register of regulated product applications: RP-1777, application for the approval of urolithin A as a novel food (Amazentis SA), status “In progress”, phase “Risk assessment”. Checked 1 November 2026. Link
10. Advisory Committee on Novel Foods and Processes. Urolithin A discussion paper (application RP1777) and 173rd meeting summary. Link
11. European Commission. Union list of novel foods (Commission Implementing Regulation (EU) 2017/2470 and amendments; page lists amendments to July 2026, no entry for urolithin A) and Summary of applications and notifications. Link (accessed 1 November 2026)
12. da Costa Pinaffi-Langley AC, Gulej R, Kaposzta Z, et al. Urolithin A and Endothelial and Cerebrovascular Function in Middle-Aged Adults With Obesity: A Randomized Clinical Trial. JAMA Netw Open. 2026. PubMed · DOI