Guides · Urolithin A

Urolithin A: what the human trials show, and what they do not

Urolithin A is a compound your gut bacteria make from ellagitannins in pomegranates, berries and nuts. It switches on mitophagy (the clean-out of worn mitochondria) and extended lifespan in worms. In people it was well tolerated in trials of up to 4 months and changed blood and muscle markers of mitochondrial health. Results on performance are mixed: muscle endurance and strength improved in some measures, but several main endpoints, such as the 6-minute walk, did not. Most of the trials were funded by the company that sells it, and no study has tested whether it slows human aging.

Written by The Bioregulator Atlas editorial team · Medical review pending · Facts and prices checked Oct 7, 2026

Older adults (4 months)
Muscle endurance up; 6-minute walk and peak ATP production not significantly better than placebo(source)
Middle-aged adults (4 months)
~12% muscle strength gain; primary endpoint (peak power) not significant(source)
Immune (2025)
50 adults, 4 weeks: more naive-like CD8+ T cells vs placebo(source)
Lifespan
Extended in C. elegans worms only; no human data(source)

What urolithin A is

Urolithins are made by gut bacteria from ellagitannins and ellagic acid, found in pomegranates, some berries and nuts. People fall into different "metabotypes": some produce urolithin A, some produce other urolithins, and some produce almost none. That is one reason it is now sold directly as a supplement (best known as Mitopure).

In a 2016 study, urolithin A induced mitophagy, prevented the build-up of faulty mitochondria and extended lifespan in the worm C. elegans, and improved exercise capacity in mice and young rats.

Human trials on muscle and mitochondria

First-in-human trial: in healthy, sedentary older people, single doses and 4 weeks of 500 mg or 1,000 mg were safe, and changed blood acylcarnitines and muscle mitochondrial gene expression.

Older adults (65–90, 66 people, 1,000 mg a day for 4 months): muscle endurance in a hand and a leg muscle improved and several blood markers, including C-reactive protein, fell. But the primary endpoints, 6-minute walk distance and maximal ATP production in the hand muscle, were not significantly better than placebo.

Middle-aged adults (two doses, 4 months): muscle strength rose about 12% and the authors reported clinically meaningful gains in aerobic endurance and the 6-minute walk, but the primary endpoint, peak power output, did not. Amazentis, which sells Mitopure, sponsored this study and employs several of its authors.

Immune aging (2025)

In a randomized, double-blind trial, 50 healthy middle-aged adults took 1,000 mg a day or placebo for 4 weeks. Urolithin A expanded naive-like, less exhausted CD8+ T cells and increased their fat-burning capacity, and changed several other immune cell populations. These are lab markers of immune aging, not infections or illness. Amazentis funded the study and provided the product.

Safety

Rat toxicology studies found no genotoxicity and no adverse effects at the highest doses tested for 90 days. In the 4-month trial in older adults, adverse events did not differ from placebo. Long-term human safety beyond about 4 months has not been studied.

FAQ

Does urolithin A work?

It changes mitochondrial and immune markers in people and improved muscle endurance and strength on some measures. Several primary endpoints, such as the 6-minute walk in older adults, were not met, and no study has shown it slows aging.

Can I get urolithin A from pomegranate?

Your gut bacteria make it from ellagitannins in pomegranate, berries and nuts, but people differ: some produce urolithin A, some produce other urolithins and some produce almost none.

Is urolithin A safe?

In the 4-month trial in older adults, adverse events did not differ from placebo, and rat toxicology found no safety signal. Longer-term human data are not available.

Who funded the urolithin A research?

Most human trials were funded by Amazentis, which sells urolithin A as Mitopure, or included its employees as authors. That does not make the results wrong, but independent replication is still limited.

Does urolithin A extend lifespan?

Only in worms (C. elegans). There are no lifespan data in mammals beyond muscle-function studies in rodents, and none in people.

Do you earn money from this page?

No. This page has no paid links. We do not have an affiliate relationship with any brand that sells these supplements, so none is featured.

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Not medical advice. Medical review pending: this page has not yet been reviewed by a licensed clinician. Statements about dietary supplements have not been evaluated by the Food and Drug Administration; these products are not intended to diagnose, treat, cure or prevent any disease. Compounded medicines are not FDA-approved. Prices change often; confirm on the seller's page.