Urolithin A is a gut microbiome–derived compound produced from ellagitannins found in foods like pomegranates, berries, almonds, and walnuts, and is linked to improved mitochondrial function and potential heart health benefits.

Natural dietary sources support urolithin A production if gut bacteria can convert ellagitannins; pomegranate juice can inhibit CYP3A4 and affect medication metabolism, while probiotics may boost production by supporting a healthy microbiome.

Safety data from trials indicate no significant adverse effects at 1,000 mg/day, but high-dose safety and drug interactions should be considered, especially with existing medications.

Clinical trial evidence suggests benefits for older adults in muscle function and inflammation (e.g., increased 6-minute walk distance and reduced CRP with 1,000 mg/day), with smaller or mixed benefits in middle-aged or younger athletes and some cardiovascular/other indications showing mixed results.

Genetic and microbiome factors influence urolithin A production, and future research requires large, independent trials to establish dosing and efficacy beyond current findings.

Supplement quality varies, with some products not meeting label claims; absorption studies show urolithin A levels can increase approximately sixfold with supplements compared to diet.

Limitations include potential industry funding bias in trials and the possibility that younger, healthy individuals may derive less benefit than older or less fit individuals.

Only about 40% of people naturally produce detectable urolithin A on a standard diet, with daily pomegranate juice intake increasing this to around 40%, and a 500 mg supplement raising plasma levels sixfold.

Urolithin A may promote mitophagy and enhance mitochondrial energy production under stress, and it has anti-inflammatory and immune-regulatory effects, including downregulating COX2 and reducing IL-1β response.

The gut microbiome determines whether individuals are converters, non-converters, or produce intermediate urolithin metabolites, with specific microbes such as Enterocloster species, Gordonibacter, and Ellagibacter involved in the pathway.