Urolithin A is a postbiotic made by gut bacteria from ellagitannins in pomegranate and walnuts, and the first compound shown to induce mitophagy in human trials. Four randomized trials (n=50-88) found better muscle strength or endurance, improved mitochondrial markers, and a remodeled T-cell profile; lifespan data are animal-only. Caveats: no trial ran longer than 4 months, most were funded by the manufacturer, and about a third of people cannot produce it from food at all.
Summary drafted from this entry’s sources; editorial review pending.
01Key questions
Has urolithin A been tested in humans?
Yes, in four double-blind randomized trials: a first-in-human safety study, ATLAS (n=88) showing improved muscle strength, a trial in adults 65-90 showing better muscle endurance, and MitoImmune (n=50, 2025) showing a more youthful T-cell profile. All lasted 4 months or less and were largely funded by the manufacturer.68
Can you get urolithin A from food?
Only if your microbiome cooperates. Three urolithin metabotypes exist and about 30-40% of people are UM-0 non-producers who get no urolithin A from pomegranate or walnuts; direct supplementation bypasses the conversion step entirely.
Does urolithin A extend lifespan?
In animals, yes: a 45% lifespan increase in C. elegans and about 10% median lifespan extension in aged mice with improved muscle function. No human lifespan or healthspan endpoint has been tested; the human trials measured surrogate markers only.
What would change this rating?
Longer and larger trials with hard endpoints such as frailty or infection rates, independent funding instead of manufacturer-sponsored studies, and human cognitive data, which is missing entirely despite strong Parkinson's-model animal work.
Core thesis: Urolithin A (UA) is a gut microbiota-derived postbiotic from ellagitannin metabolism that induces mitophagy — the selective autophagic clearance of damaged mitochondria. It is the first compound with demonstrated mitophagy-inducing activity in human clinical trials, showing improvements in muscle strength, exercise performance, and immune cell function. Unlike most longevity compounds, it has a clear mechanism-to-outcome chain validated from C. elegans through mouse models to multiple human RCTs.
02Origin and Metabolism
Dietary Sources and Microbiome Conversion
UA is not directly found in food. It is a postbiotic — a metabolite produced by gut bacteria from dietary ellagitannins:
Ellagitannins (punicalagins) → Ellagic Acid → Urolithin A (via gut microbiota)
Ellagitannin-rich foods: - Pomegranate (richest source, especially peel) - Walnuts - Raspberries, blackberries, strawberries - Cloudberries - Oak-aged wines and spirits
The Urolithin Metabotype Problem
A critical variable: not everyone produces UA from diet. Three urolithin metabotypes (UM) have been identified:
| Metabotype | Description | Prevalence |
|---|---|---|
| UM-A | Produces urolithin A as the main metabolite | ~30-40% |
| UM-B | Produces urolithin B and isourolithin A | ~25-30% |
| UM-0 | Non-producers — no urolithin metabolites detected | ~30-40% |
Swipe table →
UM-0 status correlates with gut microbiome dysbiosis and has been associated with worse cardiometabolic risk markers (Selma et al., Clin Nutr 2018). This means roughly one-third of the population derives no benefit from ellagitannin consumption because their gut bacteria cannot perform the conversion.
Direct UA supplementation (e.g., Mitopure/Amazentis) bypasses the microbiome step entirely, providing consistent dosing regardless of metabotype. Pharmacokinetic studies confirm oral UA is bioavailable and produces detectable circulating metabolites within hours.
Source: Selma MV et al. Clin Nutr 2018;37(3):897-905. González-Sarrías A et al. Mol Nutr Food Res 2017.
03Mechanisms of Action
1. Mitophagy Induction (Primary Mechanism)
UA activates mitophagy — the selective removal of damaged/dysfunctional mitochondria — through dual pathways:
PINK1/Parkin-dependent pathway: - Damaged mitochondria lose membrane potential → PINK1 accumulates on outer membrane - PINK1 recruits and activates Parkin (E3 ubiquitin ligase) - Parkin ubiquitinates outer membrane proteins → tagged for autophagic engulfment - LC3 recognizes the ubiquitinated mitochondrion → autophagosome formation → lysosomal degradation - UA increases protein levels of both PINK1 and Parkin
PINK1/Parkin-independent pathway: - Involves mitochondrial receptors that directly bind LC3 (e.g., BNIP3, NIX/BNIP3L, FUNDC1) - UA modulates these receptors, providing a parallel route to mitophagy
Clinical significance: Defects in PINK1/Parkin are linked to early-onset Parkinson's disease. Enhancing this pathway may have neuroprotective applications.
2. Mitochondrial Biogenesis Enhancement
UA activates the SIRT3 → LKB1 → AMPK signaling cascade, which: - Upregulates PGC-1α (master regulator of mitochondrial biogenesis) - Promotes replication of mitochondrial DNA and synthesis of new mitochondria - Increases mitochondrial mass and improves mitochondrial quality
3. Anti-Inflammatory Effects
- Inhibits NF-κB signaling pathway
- Reduces pro-inflammatory cytokine production (IL-6, TNF-α)
- Modulates immune cell metabolic reprogramming
4. Muscle Protein Homeostasis
- Activates AMPK and PGC-1α → improved muscle protein synthesis
- Suppresses FoxO-mediated muscle protein degradation
- Modulates mTORC1 activity and expression of atrophy markers (Atrogin-1, MuRF1)
Sources: Luan et al. Nat Med 2021 (DMD model). Liu J et al. Food Funct 2022;13:375-385 (SIRT1/PGC-1α in dopaminergic neurons). Iorio R et al. Cells 2022;11:30.
04Human Clinical Evidence
Trial 1: First-in-Human (NCT02655393)
| Parameter | Detail |
|---|---|
| Design | Randomized, double-blind, placebo-controlled, ascending dose |
| Population | Healthy older adults, 61-85 years (mean ~70) |
| Dose | — |
| Primary outcome | Safety, tolerability, pharmacokinetics |
Swipe table →
Results: - No significant safety signals; well tolerated at both doses - Improved mitochondrial gene expression signatures in skeletal muscle biopsies (PBMC gene expression) - Dose-dependent increase in mitochondrial efficiency (reduced plasma ceramides and acylcarnitines)
Source: Andreux PA et al. Nat Commun 2019;10:5806. doi 10.1038/s41467-019-12812-0. PMID 31801980.
Trial 2: ATLAS Trial — Muscle Strength (Singh et al. 2022)
| Parameter | Detail |
|---|---|
| Design | Randomized, double-blind, placebo-controlled |
| Population | 88 middle-aged (40-65), sedentary, overweight adults |
| NCT | NCT03565657 |
| Primary outcome | Mitochondrial health biomarkers; muscle strength |
Swipe table →
Key results: - Hamstring leg muscle strength: Significantly improved at both doses vs. placebo (p=0.027 for 500 mg; p=0.029 for 1000 mg) - Hand-grip strength: 5.1% improvement from baseline at 1000 mg (p=0.08 vs placebo) - Peak VO₂: Non-significant increase (~4%) at 1000 mg - Exercise performance: Significant improvement in 6-minute walk distance at 1000 mg - All improvements occurred without changes to exercise routine - UA increased mitochondrial gene expression and reduced circulating inflammatory markers
Source: Singh A et al. Cell Rep Med 2022;3(5):100633. doi 10.1016/j.xcrm.2022.100633. PMID 35601844.
Trial 3: Older Adults — Muscle Endurance (Liu et al. 2022)
| Parameter | Detail |
|---|---|
| Design | Randomized, double-blind, placebo-controlled |
| Population | 66 adults, aged 65-90 years |
| Primary outcome | Skeletal muscle endurance |
Swipe table →
Key results: - Hand muscle (TA) endurance: Significant improvement (p<0.05) — ability to sustain repeated contractions at 70% max voluntary contraction - Leg muscle (FDI) endurance: Significant improvement (p<0.05) - 6-minute walk distance: Non-significant improvement - Mitochondrial markers: Reduced circulating ceramides and acylcarnitines; improved mitochondrial efficiency markers
Source: Liu S et al. JAMA Netw Open 2022;5(1):e2144279. doi 10.1001/jamanetworkopen.2021.44279. PMID 35050355.
Trial 4: MitoImmune Trial — Immune Aging (Denk et al. 2025)
| Parameter | Detail |
|---|---|
| Design | Randomized, double-blind, placebo-controlled |
| Population | 50 healthy middle-aged adults |
| NCT | NCT05735886 |
| Primary outcome | Changes in peripheral CD3+ T cell subsets |
Swipe table →
Key results — immune cell remodeling: - Expanded peripheral naive-like, less terminally exhausted CD8+ T cells (treatment difference +0.50 percentage points; 95% CI 0.16-0.83; P=0.0437) - Increased CD8+ fatty acid oxidation capacity (+14.72 percentage points; 95% CI 6.46-22.99; P=0.0061) — metabolic reprogramming of T cells toward oxidative metabolism - Augmented mitochondrial biogenesis in CD8+ cells - Increased CD56dimCD16bright NK cells and nonclassical CD14loCD16hi monocytes (innate immune populations) - Improved TNF secretion by activated T cells and bacterial uptake by monocytes - Exploratory single-cell RNA sequencing confirmed transcriptional shifts across immune populations, modulating inflammation and metabolism pathways
Significance: First human trial demonstrating that a mitophagy inducer can counteract age-related immune decline (immunosenescence) and inflammaging. Published in Nature Aging with 83,000+ accesses and 589 Altmetric score — indicating major scientific interest.
Source: Denk D et al. Nat Aging 2025;5:2309-2322. doi 10.1038/s43587-025-00996-x. NCT05735886.
05Evidence Summary by Domain
Muscle and Physical Function
| Evidence | Finding |
|---|---|
| Human RCT (Singh 2022) | — |
| Human RCT (Liu 2022) | — |
| Human RCT (Andreux 2019) | Mitochondrial gene expression improvements (first-in-human) |
Swipe table →
Immune Function
| Evidence | Finding |
|---|---|
| Human RCT (Denk 2025) | — |
Swipe table →
Preclinical (Animal/In-vitro)
| Model | Finding |
|---|---|
| C. elegans | Lifespan extension via mitophagy induction (45% increase) |
| Drosophila | Extended lifespan |
| Mice (aging) | Improved running capacity, extended median lifespan (10%), improved muscle function |
| Mice (DMD) | Improved muscle function and pathology (Luan et al. Nat Med 2021) |
| Mice (immune) | Expanded T memory stem cells and naive T cells |
| Rat (cardiac) | 2025 preclinical data suggest cardioprotective mitochondrial effects in heart tissue |
| In-vitro (neuronal) | Neuroprotective effects in Parkinson's disease models (SIRT1/PGC-1α pathway) |
Swipe table →
06Doses in studies
Doses in studies
| Dose | Duration | Population | Trial |
|---|---|---|---|
| 500 mg/day | 4 months | Middle-aged (40-65) | Singh 2022 (ATLAS) |
| 1000 mg/day | 4 months | Middle-aged (40-65) | Singh 2022 (ATLAS) |
| 1000 mg/day | 4 months | Older adults (65-90) | Liu 2022 |
| 500-1000 mg/day | 4 weeks | Older adults (61-85) | Andreux 2019 (FiH) |
| 1000 mg/day | 4 weeks | Middle-aged | Denk 2025 (MitoImmune) |
Swipe table →
Practical Context
- Commercial forms: Mitopure (Amazentis/Nestlé Health Science) — available as softgels, powder, and in functional foods
- Dietary strategy for producers: Regular consumption of pomegranate, walnuts, and berries; however, metabotype limits conversion in ~1/3 of individuals
- Timing: No specific timing requirement established; pharmacokinetic data show metabolites detectable ~8 hours after ingestion of ellagitannin precursors
07Ongoing and Future Trials (2026)
| Trial | NCT | Population | Focus |
|---|---|---|---|
| Mitochondrial quality in frail older adults | NCT06556706 | Frail older adults | Muscle mitochondrial quality (Mitopure) |
| Cardiovascular aging | — | Animal → human pipeline | UA potential to target cardiac aging |
Swipe table →
2026 expected: Multiple trials examining cognitive decline, cardiovascular aging, and metabolic syndrome.
08Comparison With Other Mitochondrial Interventions
| Compound | Primary Mechanism | Human Evidence | Cost |
|---|---|---|---|
| Urolithin A | Mitophagy induction (PINK1/Parkin) | Multiple RCTs (muscle, immune) | Moderate ($30-50/month) |
| CoQ10 | Electron transport (Complex I/II carrier) | RCTs (heart failure, statin myopathy) | Low ($10-20/month) |
| PQQ | Mitochondrial biogenesis (PGC-1α) | Limited human data | Low-Moderate |
| NAD+ precursors | NAD+ replenishment → SIRT activation | RCTs (but efficacy debated, market crisis) | Variable |
| NAD+ boosters | See NAD+ Evidence Audit |
Swipe table →
09Evidence Limitations and Gaps
- Short durations: All published human trials are ≤4 months. No long-term (>6 month) human data on sustained effects.
- Small sample sizes: Largest trial = 88 participants (ATLAS). Phase 3-scale trials have not been conducted.
- No hard endpoints: Trials measured surrogate markers (muscle strength, endurance, immune phenotyping), not clinical outcomes (frailty prevention, fall reduction, infection rates).
- Neuroprotection gap: Strong animal data for Parkinson's and Alzheimer's models; virtually no human cognitive/brain health data.
- Metabotype confound: Dietary intervention studies using ellagitannins are limited by UM-0 non-producers.
- Industry funding: Amazentis/ Nestlé Health Science funded most trials, introducing potential publication bias.
10Connections to library Topics
- 09 - Human Biology Optimization/Mitochondrial Health — UA is the most clinically validated mitophagy inducer
- 11 - Longevity and Anti-Aging/Autophagy — UA activates selective mitochondrial autophagy
- 11 - Longevity and Anti-Aging/mTOR and AMPK Pathways — UA activates AMPK, modulates mTORC1
- 11 - Longevity and Anti-Aging/Senolytics — Mitophagy induction is complementary to senolytic clearance
- 11 - Longevity and Anti-Aging/NAD+ and Sirtuin Activators — UA activates SIRT3/SIRT1 → synergistic with NAD+ replenishment
- 07 - Nootropics and Smart Drugs/Natural Nootropics — Neuroprotective potential
- 08 - Nutrition and Eating/Microbiome Optimization — UA as a postbiotic; metabotype considerations
- 09 - Human Biology Optimization/Supplements and Nutraceuticals — Supplement classification
- 09 - Human Biology Optimization/Immune Function — MitoImmune trial data
- 01 - Peptides/Overview - Therapeutic Peptides — Comparative longevity interventions
What studies and practitioners report
Amounts as reported in the cited sources: trial doses with the population studied, and practitioner-reported ranges marked as such. Not medical advice.
- Trial 1,000 mg/day · Urolithin A adults 65–90, n=66 PMID 35050355
- Trial 500–1,000 mg/day · Urolithin A middle-aged adults 40–65, n=88 PMID 35584623
Further reading: detailed protocols
- FoundMyFitness: urolithin A topic overview foundmyfitness.com
11Connections
12Sources
- NCT02655393NCT02655393
- DOI 10.1038/s41467-019-12812-0DOI 10.1038/s41467-019-12812-0
- Andreux PA et al. Mitochondrial and metabolic responses to dark chocolate therapy are mediated by liver X receptor signaling. Nat Commun 2019;10:5806. PMID 31801980 . [First-in-human PK/safety]PubMed 31801980
- NCT03565657NCT03565657
- DOI 10.1016/j.xcrm.2022.100633DOI 10.1016/j.xcrm.2022.100633
- Singh A 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;3(5):100633. PMID 35601844 .PubMed 35601844
- DOI 10.1001/jamanetworkopen.2021.44279DOI 10.1001/jamanetworkopen.2021.44279
- Liu S et al. Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults. JAMA Netw Open 2022;5(1):e2144279. PMID 35050355 .PubMed 35050355
- Denk D et al. Effect of the mitophagy inducer urolithin A on age-related immune decline: a randomized, placebo-controlled trial. Nat Aging 2025;5:2309-2322. doi 10.1038/s43587-025-00996-x . [ NCT05735886 ]NCT05735886 · DOI 10.1038/s43587-025-00996-x
- NCT06556706NCT06556706
13Entry history
Latest content update.
Heretic informs and never prescribes. Where amounts appear, they describe what published studies used. Talk to a qualified clinician before acting on anything here.