Urolithin A
A gut-microbiome metabolite of ellagitannins (from pomegranate and walnuts) that induces mitophagy — the recycling of damaged mitochondria. Because many people cannot produce it from food, it is sold as a standardised supplement, and human trials show it improves mitochondrial and muscle biomarkers, though effects on hard outcomes are modest.
01 Overview
Urolithin A is produced by gut bacteria from ellagitannins found in pomegranate, walnuts, and berries, but only a minority of people harbour the microbiota needed to make meaningful amounts, motivating direct supplementation. It is a leading mitophagy inducer, prompting cells to clear dysfunctional mitochondria, a process that declines with age.
In animals it extends lifespan in C. elegans and improves muscle function in rodents. Human randomised trials (e.g. with the standardised compound Mitopure) show it is safe, improves mitochondrial gene expression and some measures of muscle endurance, and modestly raises muscle strength in older adults, though changes in whole-body performance have been small. It has FDA GRAS status.
02 Mechanism
Induces mitophagy, promoting removal and turnover of damaged mitochondria and improving mitochondrial quality and biogenesis in muscle and other tissues.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 500–1000 mg/day | Oral | Doses of 500-1000 mg/day used in human trials. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Induces mitophagyUpregulates mitophagy and mitochondrial gene expression in human skeletal muscle. | measurable gene-expression shift | Clinical | |
| Improved muscle endurance / strengthImproved muscle endurance and some strength measures in older adults in RCTs. | modest | Clinical | |
| Lifespan extension (worms) / muscle benefit (rodents)Extends lifespan in C. elegans and improves muscle function in aged rodents. | moderate | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Well tolerated / minimal effectsTrials report a safety profile similar to placebo; rare mild GI complaints. | Mild | Rare | Clinical | |
| Limited long-term dataSafety beyond several months of use is not established. | Mild | Uncharacterised | Unconfirmed |