Urolithin A and the Liver: What to Know

The liver processes almost everything you swallow, so it is a smart organ to think about before starting any daily supplement. Here is what human research on urolithin A shows about tolerability, what remains preclinical, and why anyone with a liver condition should involve their clinician.

Why the liver is the right thing to ask about

The liver is the body's central metabolic hub. It filters blood arriving from the digestive tract, packages nutrients, and chemically transforms a huge range of compounds so they can be used or eliminated. Much of that transformation happens through conjugation, where the liver attaches molecules such as glucuronide or sulfate groups to a compound to make it easier to clear. Because nearly every oral supplement passes through this system, asking how the liver handles a new ingredient is exactly the right instinct.

Urolithin A fits that question in an interesting way. It is a gut postbiotic: your microbiome makes it from ellagitannins, the natural precursors in pomegranate, walnuts, and certain berries. Not everyone's gut bacteria convert those precursors efficiently, which is part of why a standardized supplement exists. After absorption, urolithin A undergoes first-pass metabolism and is largely conjugated in the body, and these conjugated metabolites are what circulate. This is normal handling for many dietary polyphenol metabolites, and it is why the liver is naturally part of the conversation.

What urolithin A is actually designed to support

Urolithin A is studied for one core reason: mitophagy. Mitochondria are the power plants inside your cells, and some inevitably become worn or damaged over time. Mitophagy is the quality-control process that flags these underperforming mitochondria and recycles them so fresher ones can take over. In laboratory and animal studies, urolithin A supports this recycling. Our urolithin A guide and our explainer on mitophagy unpack the mechanism, and our overview of mitochondrial health puts it in context. The important framing for this page: urolithin A is studied as general mitochondrial support, not as a liver product.

What the human evidence shows about tolerability

Let us organize the evidence by strength, and label human versus preclinical clearly.

First-in-human safety (HUMAN)

The cornerstone is Andreux and colleagues (2019, Nature Metabolism), the first-in-human study of urolithin A. It reported that the compound was safe and well tolerated at single and repeated doses up to 1,000 mg per day, alongside a measurable mitochondrial gene-expression signature. Tolerability was assessed in generally healthy adults, not in people with liver disease.

Repeated-dosing trials (HUMAN)

Subsequent controlled trials gave urolithin A to generally healthy adults, often for around four months. Liu, D'Amico and colleagues (2022, JAMA Network Open) reported improved muscle endurance in older adults. Singh and colleagues (2022, Cell Reports Medicine) used 500 mg and 1,000 mg daily arms in middle-aged adults and reported effects on muscle strength and exercise performance. A 2025 Nature Aging randomized trial of about 28 days reported support for immune-cell mitochondrial health in midlife adults. An 8-week randomized trial in resistance-trained men (Journal of the International Society of Sports Nutrition, 2024) looked at endurance and recovery markers. Across these studies urolithin A was generally well tolerated. Once again, the participants were broadly healthy adults, and these trials were not designed to evaluate people with liver disease.

Where the liver research is still preclinical

You may see claims that urolithin A is “liver-supportive.” Read those carefully. Much of that discussion draws on preclinical research — studies in cultured hepatocytes (liver cells in a dish) and in animal models exploring how urolithin A behaves in the liver. Early and preclinical research is exploring these questions, and that work is genuinely interesting to scientists. But preclinical does not mean proven in people. Cells and mice are not humans, and a signal in a model is a reason to keep studying, not evidence that a supplement will do anything for your liver. SOMA HEALTH does not claim that urolithin A treats, protects, or improves any liver condition, because the human evidence to support such a claim does not exist.

Modeling work has also looked at urolithin A's bioavailability and safety margins, generally suggesting that the amounts reached in the body from supplementation sit well below concentrations linked to toxicity in laboratory settings. That is reassuring context for tolerability, but it is not a therapeutic claim, and it does not replace medical advice for anyone with a compromised liver.

Practical guidance if your liver is a consideration

Involve your clinician if you have any liver condition

If you have fatty liver, hepatitis, cirrhosis, elevated liver enzymes, or any other liver diagnosis, do not start urolithin A on your own. Your care team should weigh in on anything you take daily, because a compromised liver changes how the body processes many substances. This is a structure/function supplement, not a treatment for any liver condition.

Stay within the studied dose

The clinically studied range is 500 to 1,000 mg per day, with 1,000 mg at the top of that range. There is no benefit to exceeding what has been tested. See our dosage page for the full breakdown, and our side effects and safety overview for what to watch for.

Be mindful of everything else you take

If you regularly use alcohol, over-the-counter pain relievers, or other supplements that the liver processes, it is worth reviewing your total load with a pharmacist or clinician. This is general good practice, not a warning specific to urolithin A.

Choose a third-party tested product

When you take something daily, purity is not a luxury. The SOMA HEALTH Urolithin A Gummies provide 1,000 mg per four-gummy serving, are third-party tested, and are sugar-free. If you are comparing brands, our guide to the best urolithin A gummies explains what a quality product should demonstrate.

Not a treatment — see your doctor. Nothing on this page is intended to diagnose, treat, or manage any liver condition. If you have liver symptoms or a diagnosed liver problem, your clinician is the right person to guide what you take.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This guide is educational and is not a substitute for advice from a qualified healthcare provider.