What the evidence says. Early or small human trials; promising but not yet conclusive.
What is Urolithin A?
Urolithin A is a longevity supplement used for improved skeletal muscle endurance (more contractions to fatigue) in older and resistance-trained adults in small rcts. NutriDex grades the human evidence as Preliminary. Urolithin A is a metabolite produced by gut bacteria from ellagitannins found in pomegranate, walnuts, and certain berries, though only some people carry the microbes needed to make it efficiently. Its main mechanism of interest is stimulating mitophagy, the cellular clearance of damaged mitochondria, which has driven its marketing as a longevity and muscle-health supplement (commonly as the standardized ingredient Mitopure). Small, mostly industry-supported randomized trials in older, middle-aged, and athletic adults report improvements in muscle endurance and favorable shifts in mitochondrial and inflammatory blood biomarkers, but results on hard endpoints like muscle strength, peak ATP production, and the 6-minute walk test have been inconsistent and sometimes not statistically significant. No trial has demonstrated long-term clinical outcomes such as reduced disability, falls, or improved survival. Short-term safety in studies up to several months appears good, but the overall evidence base remains preliminary and limited in size, duration, and independent replication.
Purported Benefits
✓Improved skeletal muscle endurance (more contractions to fatigue) in older and resistance-trained adults in small RCTs
✓Favorably shifted mitochondrial-health blood markers (acylcarnitines, ceramides) and reduced C-reactive protein
✓Modest gains in muscle strength and exercise performance reported in middle-aged adults, though not consistent across endpoints
✓Stimulates mitophagy (recycling of damaged mitochondria), a mechanism of interest for healthy aging
✓Generally well tolerated with a favorable short-term safety profile at studied doses
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
500–1000 mg once daily of standardized urolithin A (e.g., Mitopure), taken with food; most trials used 1000 mg/day for 4 months.
Active Compounds
Urolithin A (a dibenzo[b,d]pyran-6-one; gut-microbiota metabolite of ellagitannins/ellagic acid)Synthesized/standardized form marketed as Mitopure
Safety & Cautions
⚠
Urolithin A has a favorable short-term safety profile in trials up to about 4 months at 250–1000 mg/day, with adverse-event rates similar to placebo and no serious adverse events reported; mild gastrointestinal complaints are the most common issue. Long-term safety beyond a few months is unstudied. Safety has not been established in pregnancy or breastfeeding, or in children, so these groups should avoid it. People with significant liver or kidney disease and those on multiple medications should consult a clinician first, as metabolism, drug interactions, and effects on disease are not well characterized; theoretical interactions with drugs cleared by the liver cannot be excluded. It is a dietary supplement and is not regulated as a drug, so product purity and dosing accuracy vary by brand—choose standardized products (e.g., Mitopure). It is not a treatment for any disease, and anyone with a medical condition or taking prescription medications should discuss use with a healthcare provider before starting. Educational only — always check with your doctor or pharmacist before combining Urolithin A with any medicine.
Urolithin A is most often taken for Improved skeletal muscle endurance (more contractions to fatigue) in older and resistance-trained adults in small RCTs, Favorably shifted mitochondrial-health blood markers (acylcarnitines, ceramides) and reduced C-reactive protein, Modest gains in muscle strength and exercise performance reported in middle-aged adults, though not consistent across endpoints, Stimulates mitophagy (recycling of damaged mitochondria), a mechanism of interest for healthy aging. Gut-derived pomegranate metabolite that triggers mitophagy; early trials hint at better muscle endurance.
Does Urolithin A work — what does the evidence say?
Preliminary evidence. Early or small human trials; promising but not yet conclusive. Urolithin A is a metabolite produced by gut bacteria from ellagitannins found in pomegranate, walnuts, and certain berries, though only some people carry the microbes needed to make it efficiently. Its main mechanism of interest is stimulating mitophagy, the cellular clearance of damaged mitochondria, which has driven its marketing as a longevity and muscle-health supplement (commonly as the standardized ingredient Mitopure). Small, mostly industry-supported randomized trials in older, middle-aged, and athletic adults report improvements in muscle endurance and favorable shifts in mitochondrial and inflammatory blood biomarkers, but results on hard endpoints like muscle strength, peak ATP production, and the 6-minute walk test have been inconsistent and sometimes not statistically significant. No trial has demonstrated long-term clinical outcomes such as reduced disability, falls, or improved survival. Short-term safety in studies up to several months appears good, but the overall evidence base remains preliminary and limited in size, duration, and independent replication.
What is the typical dose of Urolithin A?
500–1000 mg once daily of standardized urolithin A (e.g., Mitopure), taken with food; most trials used 1000 mg/day for 4 months.
Is Urolithin A safe? Any cautions or side effects?
Urolithin A has a favorable short-term safety profile in trials up to about 4 months at 250–1000 mg/day, with adverse-event rates similar to placebo and no serious adverse events reported; mild gastrointestinal complaints are the most common issue. Long-term safety beyond a few months is unstudied. Safety has not been established in pregnancy or breastfeeding, or in children, so these groups should avoid it. People with significant liver or kidney disease and those on multiple medications should consult a clinician first, as metabolism, drug interactions, and effects on disease are not well characterized; theoretical interactions with drugs cleared by the liver cannot be excluded. It is a dietary supplement and is not regulated as a drug, so product purity and dosing accuracy vary by brand—choose standardized products (e.g., Mitopure). It is not a treatment for any disease, and anyone with a medical condition or taking prescription medications should discuss use with a healthcare provider before starting.
How many studies support Urolithin A?
NutriDex cites 13 sources for Urolithin A, graded "Preliminary".
Cite this page
APA
Peh, D. (2026). Urolithin A: Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/urolithin-a
BibTeX
@misc{nutridex_urolithin_a,
author = {Peh, Daryl},
title = {Urolithin A: Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/urolithin-a},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.