Short answer: Urolithin A is a compound your gut bacteria make from pomegranates, walnuts and berries. In randomised trials, 500–1,000mg a day for four months modestly improved muscle endurance and strength in middle-aged and older adults. It is one of the better-supported longevity supplements, but the effects are small and the trials were funded by the company that makes the tested ingredient.

What Is Urolithin A?

Urolithin A is produced in the gut when bacteria break down ellagitannins, plant compounds found in pomegranates, walnuts and some berries. The catch is that many people don’t have the gut bacteria to make much of it, so eating pomegranates doesn’t guarantee you get any. Supplements supply it directly.

Interest comes from mitophagy, the process cells use to clear damaged mitochondria. Animal studies first suggested Urolithin A could switch this process on, and that led to human trials.

What Do Human Trials Show?

Older adults (Liu et al., 2022)

In a randomised trial in 66 adults aged 65–90, 1,000mg of Urolithin A daily for four months did not improve the main outcomes, 6-minute walk distance and peak ATP production in muscle. It did improve muscle endurance in a hand muscle and a leg muscle, measured as the number of contractions before fatigue. Some blood markers, including CRP and certain ceramides, also fell compared with placebo.

Middle-aged adults (Singh et al., 2022)

In the ATLAS trial, 88 sedentary adults aged 40–64 took 500mg or 1,000mg daily for four months. Leg muscle strength improved by about 10–12% compared with placebo, and the higher dose improved some endurance measures. The primary endpoint, peak power output, was not significant.

Urolithin A Benefits: What’s Supported and What Isn’t

How Much Urolithin A Should You Take?

Human trials used 500mg or 1,000mg once a day for up to four months. There’s no evidence that more than 1,000mg works better. Starting at 500mg is reasonable, and most of the trial benefit appeared at 1,000mg.

Side Effects and Safety

Urolithin A was well tolerated in both trials. Adverse events were similar to placebo and none were serious. Long-term data beyond four months is limited.

Where to Buy Urolithin A (and a US Warning)

Aeternum sells Urolithin A as 500mg capsules (£50 for 60) and as a powder with a 500mg scoop (£45 for 30g, about 60 scoops). That works out to about £0.75–£0.83 a day at 500mg. These are UK display prices on 14 November 2026. Aeternum doesn’t ship Urolithin A to the United States. US readers will need a US-available brand.

Prefer powder? See Aeternum Urolithin A powder. Read our full Aeternum review for the brand’s strengths and weaknesses.

Why Pomegranates Aren’t Enough for Most People

Your body only gets Urolithin A from food if your gut bacteria can make it. They convert ellagitannins from pomegranates, walnuts and some berries, first into ellagic acid and then into urolithins. People differ a lot in how well their microbiome does this.

In a 2022 study of 100 healthy adults who drank pomegranate juice, only around 40% produced meaningful levels of Urolithin A. The rest made little or none. Producers had more diverse gut bacteria. In the same study, taking 500mg of Urolithin A directly raised blood levels consistently, whatever the person’s gut type. That’s the main practical argument for supplementing rather than relying on diet.

Capsules or Powder?

Aeternum sells both. The capsules are 500mg each, with a two-capsule (1,000mg) label serving. The powder comes with a 500mg scoop, has no fillers, and is slightly cheaper per gram. Choose capsules for convenience and exact doses. Choose powder if you want the lowest cost per dose and don’t mind measuring.

How to Take Urolithin A

• Dose: 500mg a day to start; 1,000mg matches the higher trial dose.
• Timing: once daily. In the older-adult trial it was taken in the morning on an empty stomach with water, but no trial has compared timings.
• Duration: trial benefits appeared at two months and grew by four. Judge it after at least 8–12 weeks.
• Combine with exercise: the trials studied mostly sedentary people. Exercise also triggers mitophagy, and no supplement replaces it.

Urolithin A vs CoQ10 vs NMN

These three are often stacked together, but they do different jobs. Urolithin A is meant to help clear out damaged mitochondria. CoQ10 is part of the mitochondrial energy chain itself. NMN feeds NAD+, a coenzyme mitochondria rely on.

How to Check Quality

Urolithin A is a single molecule, so quality comes down to purity and dose accuracy. Before you buy any brand, look for a certificate of analysis (COA) from an independent lab. It should show purity (ideally over 98%), the batch number, and tests for heavy metals and microbes. Aeternum links to a current third-party COA on its Urolithin A page. Check that the batch on the certificate is recent.

Urolithin A FAQ