Urolithin A: What Human Trials Have Studied and Who Funded Them
Urolithin A has been studied in 7 human trials. They measured muscle endurance and strength in populations from sedentary 70-year-olds to elite distance runners. 5 of those 7 trials are funded by, and co-authored by employees of, Amazentis SA, the company that owns the Mitopure brand and the underlying patents. Only Zhao 2024 is fully independent. The Amazentis-funded trials used Mitopure-branded urolithin A at 500-1,000mg/day depending on the trial. Timeline sells Mitopure direct to consumers, not on Amazon that we found, and whether the independently-funded trials used the same branded material is not established. The two Amazon products we track differ from the trial material in dose per serving or in molecular form (details below).
Educational overview — not medical advice. No human trial has tested urolithin A for lifespan extension, anti-aging, or disease prevention at any dose. This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
On best urolithin A, we do not name a single trial-matched pick and explain how each option differs from the trial material.
Start here
What urolithin A is, and the funding count
Urolithin A is a metabolite the gut produces from ellagitannins, compounds found in foods like pomegranates, walnuts, and some berries. It is not an essential nutrient: there is no deficiency state, no RDA, and no government-set upper limit. Only around 40% of adults reliably convert dietary ellagitannins into meaningful urolithin A levels, and direct supplementation bypasses that gut-bacteria variability with more consistent plasma exposure (Singh 2021). That is a mechanistic finding, not evidence of a clinical benefit.
On the clinical side, 7 human RCTs have tested urolithin A, spanning sedentary older adults, untrained middle-aged adults, trained young athletes, elite distance runners, and adolescent soccer players. Read the funding roster before the results: 5 of the 7 trials are Amazentis-funded and/or co-authored by Amazentis employees or executives (Andreux 2019, Singh 2021, Liu 2022 partially, Singh 2022 fully, Whitfield 2025). Only Zhao 2024 (Jiangsu Province educational grant, explicit no-conflict-of-interest disclosure) is fully independent. It is one trial, not a replication at scale by unrelated labs. A seventh trial (Monsalve Acevedo 2025, an adolescent soccer pilot) has partial industry-adjacent funding: one author received travel reimbursement from the Mitopure manufacturer, though the primary grant was unrelated.
What the trials measured
Read the funding disclosure before the results. Singh 2022 is fully Amazentis-funded, and every author is a current or former Amazentis employee, board member, or scientific advisor. It compared 500mg and 1,000mg doses with placebo and measured hamstring strength, VO2 and walking distance. Two of the industry-funded trials, Liu 2022 (older adults) and Whitfield 2025 (elite runners), had null primary endpoints (6-minute walk distance and 3000m time-trial performance, respectively), with other findings on secondary measures. Zhao 2024, the one independent trial, measured reps-to-failure and maximal strength (1RM) in young trained athletes. See the full breakdown in the section below.
The one-line takeaway Trials reported muscle-endurance and strength measures, mostly in studies funded by the company that sells Mitopure, with no lifespan or disease-outcome data at any dose. See best urolithin A for the product comparison.
The Amazon products and the trial material
The Amazentis-funded trials (5 of the 7 in this evidence base) used Mitopure-branded urolithin A at 500-1,000mg/day depending on the trial, and Timeline sells Mitopure direct to consumers. We did not find a stable Amazon listing for it. Whether the independently-funded trials (Zhao 2024, the soccer pilot) used the same branded material is not established. That leaves two products we track on Amazon, and neither matches the trial material exactly. Pure Encapsulations Renual carries the Mitopure brand (free urolithin A, the form tested in trials) at 250mg per serving, half the lowest trial dose of 500mg, and is bundled with resveratrol and CoQ10. Nutri's urolithin A diacetate product lists 1,000mg, matching the highest trial dose number, but diacetate is an ester form, a different molecule from the free urolithin A tested in trials, and dose-equivalence between the two should not be assumed. See the comparison on best urolithin A.
On safety: no serious adverse events were reported across the trials in this pack, at doses up to 2,000mg as a single dose or 1,000mg/day for 4 months (Andreux 2019, Singh 2022, Liu 2022, Whitfield 2025). Those trials were short. There is no 6-month-plus or multi-year human safety data at any dose, and no pregnancy or breastfeeding data exists. See the dose-by-dose breakdown on the dosage guide.
On this page
Urolithin A Trials: What Was Measured and Who Funded Them
Part 1: the producer-biology rationale (genuine, not marketing)
Before getting to the funding question, it's worth understanding why direct urolithin A supplementation exists as a category at all, separate from "eat more pomegranates." Urolithin A isn't found pre-formed in food in meaningful amounts — it's a metabolite that gut bacteria produce from ellagitannins, compounds found in pomegranates, walnuts, and some berries. Singh 2021 tested this directly in over 100 healthy adults: after a pomegranate-juice challenge, only about 12% had any detectable urolithin A at baseline, and only around 40% of participants turned out to be reliable "producers" who could convert a meaningful amount of dietary ellagitannins into urolithin A via their gut microbiome at all. Direct oral urolithin A supplementation, by contrast, gave more than 6-fold higher and far more consistent plasma exposure than the pomegranate juice, independent of a person's natural producer status. That's a real, non-marketing biological reason direct supplementation might matter — it bypasses a gut-bacteria bottleneck that a majority of people apparently have. It is important to be precise about what this trial does and doesn't show, though: it's a bioavailability and pharmacokinetics study, not an efficacy trial. It explains why a pill might reach the bloodstream more reliably than pomegranate juice; it says nothing about whether reaching the bloodstream produces a clinical benefit. That question belongs to the trials in Part 2.
Part 2: the funding roster, counted explicitly
This is the single most important table on this site for urolithin A, because it changes how every other claim on this cluster should be read. Of the seven human trials in this evidence base:
| Study | Funding | What it tested |
|---|---|---|
| Andreux 2019 | Amazentis-funded — authors include the Amazentis founder/CEO and employees | First-in-human safety/PK, n=60 |
| Singh 2021 | Amazentis-funded — same author/employee set | Producer-biology/bioavailability (not efficacy) |
| Liu 2022 | Partially Amazentis-funded/co-authored (3 of 9 authors); lead site independent (University of Washington) | Sedentary older adults, n=66 |
| Singh 2022 | Fully Amazentis-funded — every author is a current/former Amazentis employee, board member, or advisor; paper states Amazentis "is the sponsor" | Untrained middle-aged adults, n=88 — the strongest positive trial in this pack |
| Zhao 2024 | FULLY INDEPENDENT — Jiangsu Province educational grant, explicit no-COI disclosure | Young trained athletes, n=20 — the one non-Amazentis trial |
| Whitfield 2025 | Amazentis-funded — 3 co-authors are Amazentis employees | Elite distance runners, n=42 |
| Monsalve Acevedo 2025 | Partially industry-adjacent — one author received travel reimbursement from the Mitopure manufacturer; primary grant unrelated (Memphasys) | Adolescent soccer players (pilot), n=20 |
5 of 7 trials are Amazentis-funded and/or Amazentis-employee-co-authored in whole or part. 1 of 7 (Zhao 2024) is fully independent. 1 of 7 (the soccer pilot) has partial, narrower industry-adjacent funding that shouldn't be lumped in with the fully-funded trials, but also isn't the same as full independence. This isn't disqualifying — industry-funded trials can be rigorous, and Singh 2022's methodology and reporting are solid by normal clinical-trial standards. But a reader deserves to know, before reading any positive finding, that the company selling the ingredient funded or staffed most of the research reporting positive results. Zhao 2024 pointing the same general direction on endurance is genuinely reassuring — independent confirmation, even partial and small-scale, is exactly the kind of evidence that should carry extra weight. It's one trial, though, in one narrow population (n=20, young already-trained athletes), not a large-scale independent replication.
Part 3: the verdict
A modest-effect-size signal on muscle endurance and fatigue resistance — more consistent across trials than raw maximal-strength gains — disclosed honestly as coming almost entirely from the company that profits from a positive result. Two of the industry-funded trials (Liu 2022, Whitfield 2025) had null primary endpoints, with the positive findings landing on secondary measures; that ordering is named throughout this cluster rather than skipped past. No serious adverse events were reported in any trial, up to 2,000mg as a single dose or 1,000mg/day for 4 months — the longest continuous human safety window in this site's newer-longevity category, even though it still falls short of a 6-month-plus long-term read. And there is no lifespan, anti-aging, or disease-outcome data at any dose, in any trial, funded or independent.
The one-line takeaway Urolithin A has genuinely more human RCT evidence behind it than most longevity-marketed ingredients — and 5 of those 7 trials were funded by the one company that stood to profit from a positive result. Zhao 2024's independent confirmation on endurance is real and worth weighting, but it's one small trial, not a large-scale replication. Read the funding line before the finding, on this page and every other page in this cluster.
Frequently asked questions
What have the urolithin A trials measured?
Across 7 trials in varied populations, muscle-endurance and strength measures were studied. 5 of 7 are Amazentis-funded (the company that sells Mitopure); only Zhao 2024 is fully independent. Two trials had null primary endpoints.
How many of the trials are funded by the company that sells it?
5 of 7 (Andreux 2019, Singh 2021, Liu 2022 partial, Singh 2022 full, Whitfield 2025). Zhao 2024 is fully independent. The soccer pilot has partial industry-adjacent funding (travel reimbursement only).
Can I buy the actual product used in the trials?
Not on Amazon that we found. The Amazentis-funded trials used Mitopure at 500-1,000mg/day depending on the trial; Timeline sells it direct to consumers. Whether the independently-funded trials used the same material is not established. The two Amazon products we track are Renual (250mg of free urolithin A per serving) and Nutri (urolithin A diacetate, a different form from the one tested in trials).
Has urolithin A been studied for aging or lifespan?
No human trial has measured lifespan or disease outcomes. All trials measured short-to-medium-term functional and biomarker endpoints.
Related guides
- NMN — another longevity-marketed ingredient where a rigorous meta-analysis found a null result the marketing skips past
- Nicotinamide Riboside — NAD+ reliably rises, but independent functional trials mostly came back null or underpowered
- Spermidine — the confirmatory human trial built to prove a benefit and didn't, on its primary endpoint
- CoQ10 — another mitochondrial-energy-adjacent supplement with its own absorption-form distinction
Sources
- Andreux PA, Blanco-Bose W, Ryu D, et al. "The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans." Nat Metab. 2019. PMID: 32694802
- Singh A, D'Amico D, Andreux PA, et al. "Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults." Cell Rep Med. 2022. PMID: 35584623
- Liu S, D'Amico D, Shankland E, et al. "Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial." JAMA Netw Open. 2022. PMID: 35050355
- Zhao J, Zhu J, Yun H, et al. "Effects of urolithin A supplementation on muscle endurance, strength, and inflammatory biomarkers in trained young athletes." J Int Soc Sports Nutr. 2024. PMID: 39487653
- Whitfield J, et al. "Urolithin A Supplementation in Highly-Trained Distance Runners During an Altitude Training Camp." Sports Med. 2025. PMID: 40839339
- Monsalve Acevedo N, et al. "Urolithin A supplementation in adolescent academy soccer players: a pilot study." Front Nutr. 2025. PMID: 41245402
- Singh A, Andreux PA, Blanco-Bose W, et al. "Direct supplementation with Urolithin A overcomes limitations of dietary exposure and gut microbiome variation." Eur J Clin Nutr. 2021. PMID: 34117375 (mechanistic/rationale citation, not an efficacy trial).
- Full product dataset: /urolithin-a/cost-by-brand.json (CC BY 4.0).