Urolithin A
Best-in-class: Mitopure by Timeline
A gut-bacterial metabolite of pomegranate ellagitannins that switches on MITOPHAGY — your cells' quality-control system for mitochondria. Most people cannot make meaningful amounts of it themselves, which is the entire reason an isolated supplement exists.
Urolithin A quick facts
| Suggested dose | 500 mg of Mitopure daily — every form, same dose. 2 softgels, or 1 powder stick, or 2 gummies. That's the trial dose and the label dose across all three, so choose on format rather than potency. Take with a meal. |
| How often | daily |
| Who it's for | Anyone over about 40 noticing recovery has slipped, and anyone building a longevity stack who wants the item with the strongest human evidence in it. |
| Best-in-class brand | Mitopure by Timeline |
One of maybe five supplements here I'd put in the top evidence tier — randomized placebo-controlled human trials, muscle biopsies confirming the mechanism in people rather than in a dish, and improvements in muscle endurance and strength over four months. The honest caveats are that the effect is modest, it is slow, and the strongest trials are company-run. This is not something you feel on Thursday. The conversion problem is also the reason generic pomegranate extract has probably done nothing for most people who tried it.
How Urolithin A actually works
Damaged mitochondria don't simply stop working — they keep consuming fuel, produce less ATP, and leak reactive oxygen species into the cell around them. Mitophagy is the quality control system that tags, dismantles and recycles them, and its efficiency declines with age, so the mitochondrial population degrades in quality even when the count looks normal. Urolithin A restarts that clearance. The reason it must be supplemented rather than eaten is the conversion step: pomegranate contains ellagitannins, not urolithin A, and only around 40% of people carry the gut bacteria that convert them.
Where to get Urolithin A
Find Urolithin A on iHerb →The evidence for Urolithin A
Graded by what exists behind each claim.
✅ Clinically validated
- Why mitophagy is the point. Mitochondria don't just fail quietly. A damaged one keeps consuming fuel while producing less ATP, and it leaks reactive oxygen species into the cell around it. So a broken mitochondrion isn't merely useless — it is actively damaging its neighborhood. Mitophagy is how the cell tags, dismantles and recycles them. That clearance rate falls with age, damaged mitochondria accumulate, and the result is the thing everyone describes identically: 'I train just as hard, I just don't recover the way I used to.'
- Mitochondrial dysfunction is one of the formally recognized hallmarks of ageing, alongside things like telomere attrition and cellular senescence — this isn't a supplement-marketing framing, it's the mainstream geroscience one.
- Randomized placebo-controlled human trials — not rodent data, not mechanism — show improved muscle endurance and strength, with the effects measured in middle-aged and older adults.
- Muscle biopsies in those trials showed changed mitochondrial gene expression, so the mechanism was confirmed IN humans rather than inferred from cells.
- Timeline's own 16-week trial reports a 39% increase in a mitochondrial renewal marker over placebo. Company-run, so weigh it accordingly — but it is a real randomized trial with a published protocol, which is more than almost any longevity supplement can say.
- Muscle is where it's been studied most, but mitochondrial quality underpins tissues that are energetically expensive and slow to replace: heart, brain, and immune cells — T-cell function in particular depends heavily on mitochondrial fitness.
📊 Correlative data
- People who naturally produce more urolithin A show better muscle and metabolic markers. Suggestive rather than causal — it may partly reflect a healthier gut microbiome overall.
🧪 Theoretical / extrapolated benefits
- The broader anti-ageing claims follow logically from the mitophagy mechanism, but muscle and mitochondrial outcomes are the ones with human data behind them. Treat cognition, immunity and cardiovascular benefit as plausible extrapolation, not established fact.
How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →
What Urolithin A actually does
Urolithin A is not a plant compound. It is a bacterial metabolite of one, and that distinction is the whole reason the product exists. Pomegranates, walnuts and berries contain ellagitannins, which hydrolyze in the gut to ellagic acid. Colonic bacteria then perform a sequence of dehydroxylations and lactone-ring reductions that produce urolithins. Human cells cannot do any of that.
The mechanism is mitophagy, which is a quality control process rather than an energy one. Damaged mitochondria lose membrane potential, PINK1 accumulates on the outer membrane and recruits Parkin, which ubiquitinates outer membrane proteins and tags the organelle for autophagic degradation. Urolithin A induces that process. The proposed benefit is not more mitochondria but a cleaner population of them Zhao 2023.
Removal and replacement are two halves of the same cycle. Selective clearance of dysfunctional mitochondria relieves the reactive oxygen species burden they impose and permits biogenesis through PGC-1alpha. That is why the reported markers are a mixture of mitophagy and biogenesis measures, and why the plasma read-outs in the trials are acylcarnitines and Cystatin C rather than anything familiar.
The distribution of the compound is itself unusual. Urolithin A is absorbed from the colon, extensively glucuronidated in the enterocyte and liver, and circulates predominantly as the glucuronide. Whether the conjugate is active, or is deconjugated at tissue by beta-glucuronidase released from inflammatory cells, is the same unresolved question that hangs over most polyphenol metabolites.
And there are three human metabotypes, which is the fact this page is built on. Intervention trials consistently sort people into producers of urolithin A, producers of the isourolithin A and urolithin B pattern, and non-producers, independently of the food source Tomas-Barberan 2014. Roughly 30 to 40 percent of people cannot make urolithin A from pomegranate at all.
Cell, rodent, human — and where it stops
The unusual thing about this page is that the surrogate and the outcome were measured in the same trials, and they came apart in a specific, informative way.
The metabotype work established the problem before the product existed. Human gut microbiota produce three consistent urolithin phenotypes across intervention trials regardless of the food source Tomas-Barberan 2014. Supplying urolithin A directly is a rational response to that, and it is one of the few supplements whose existence is justified by a measured human variation.
In middle-aged adults the trial reported both a marker and a function. A randomized trial found improvements in muscle strength and in exercise performance alongside plasma biomarkers of mitochondrial health Singh 2022. That is a stronger design than most of this catalog gets.
In older adults the primary endpoint missed and the mitochondrial markers moved. A randomized clinical trial of urolithin A supplementation in older adults reported that the primary muscle endurance endpoint was not met while measures of mitochondrial health improved Liu 2022. That is precisely the shape this whole file describes: the mechanism marker responded and the function the reader cares about did not.
The pooled picture is correspondingly cautious. A systematic review of urolithin A supplementation on muscle health outcomes in humans from randomized controlled trials summarizes a small and heterogeneous evidence base Dao 2026, and the compound's pharmacology and muscle role have been reviewed as promising rather than established Zhao 2023.
And in the population with the least headroom it did nothing. An evaluation in highly trained male distance runners examined running performance, recovery and mitochondrial biomarkers Whitfield 2025. Trained endurance athletes already have high mitochondrial quality and turnover, so a mitophagy inducer has the least to remove — which is the same baseline argument that governs half the pages in this cohort.
Urolithin A — which form, and does it matter
Buying the metabolite instead of the precursor is the entire product concept and it is a good one. Pomegranate extract, pomegranate juice and ellagic acid all depend on the consumer's microbiota to produce urolithin A, and a third or more of people cannot Tomas-Barberan 2014. Supplying the synthesized metabolite removes that lottery, which is a genuinely rational form decision and rare in this catalog.
The synthesized material is not a botanical extract and should not be priced or regulated as one. The commercial product is a chemically synthesized, defined-purity compound that has been through a formal safety notification, which is a different regulatory object from a standardized fruit extract. That is worth knowing when comparing it with a pomegranate capsule that costs a tenth as much.
The exposure numbers explain the trial dose. Oral urolithin A is absorbed and undergoes extensive first-pass glucuronidation and sulfation, so plasma is dominated by conjugates; peak plasma concentration arrives at roughly 5 to 7 hours because absorption is slow and formulation-dependent, and the terminal half-life is long enough that once-daily dosing produces accumulation over several days. There is no significant cytochrome oxidation step; disposal is by conjugation followed by biliary and renal clearance. The trial doses were 500 mg and 1,000 mg a day Singh 2022 Liu 2022.
The clock on the biology is months, not days. Mitophagy is a turnover process; the trials ran 4 months. Any protocol shorter than 8 to 12 weeks is not testing the mechanism, and the marker changes reported were at 4 months Liu 2022.
What a label cannot tell you and should. Whether the material is synthesized urolithin A or a pomegranate extract standardized to ellagitannins. Those are different products with different evidence, and the second one only works in the people who were already going to make urolithin A from food Tomas-Barberan 2014.
What would have to be true, and how you would know it was not
1. Predict the mitochondrial markers move and predict they are unfamiliar. Predict plasma acylcarnitines shift and mitochondrial gene expression measures change over 4 months at 500 to 1,000 mg a day Liu 2022 Singh 2022. These are not on a standard panel, which is itself worth stating: the marker this product owns is not one a reader can order.
2. Predict a small strength change and predict endurance is harder to move. Predict measurable improvement in a leg or hand strength test over 4 months in a middle-aged adult Singh 2022, and predict a muscle endurance endpoint in an older adult does not reach significance Liu 2022. That specific dissociation is the falsifiable claim on this page.
3. The prediction that cuts against the product. In a highly trained endurance athlete, predict no improvement in running performance or recovery, because mitochondrial quality is already high and mitophagy is already active Whitfield 2025. A trial in trained athletes showing a performance benefit would falsify this.
4. Predict the pomegranate comparison fails in a third of people. Predict that a pomegranate extract produces urolithin A in some people and isourolithin A or nothing in others, and predict that the non-producers get no benefit from the precursor Tomas-Barberan 2014. A urinary urolithin measurement after a pomegranate load is the test that would identify them, and it is a research assay.
5. Predict grip strength is the practical read-out. Grip strength is measurable at home, correlates with the outcomes these trials are aimed at, and is far more informative than a subjective energy rating. Predict a change too small to notice without a dynamometer and large enough to measure with one over 4 months Dao 2026.
What nobody has tested yet
The endpoint that would justify the price has not been reached. No trial has taken urolithin A to a functional outcome that matters clinically — falls, sarcopenia diagnosis, gait speed decline — over the years such an endpoint requires Dao 2026. Everything so far is 4 months and markers.
Nobody has stratified a trial by metabotype. The obvious hypothesis is that natural urolithin A producers respond least to supplementation because they already have it Tomas-Barberan 2014, and no trial has measured baseline metabotype and tested it. That single design change would explain most of the between-person variation.
The active species is unidentified. Circulating urolithin A is mostly glucuronide, the mitophagy work uses the aglycone, and nobody has demonstrated tissue deconjugation in humans Zhao 2023. Until that is settled, the plasma concentration reported in trials is a number of uncertain relevance.
And nobody has compared it against exercise. Endurance training is a potent, free and well-characterized inducer of mitochondrial turnover. Whether urolithin A adds anything on top of a training program, or whether it matters mainly for people who cannot train, has not been tested Whitfield 2025.
Urolithin A — its own safety story, not its category's
The tolerability record in the trials is good and it is short. Four-month randomized trials at 500 and 1,000 mg a day reported no significant safety signal, with mild gastrointestinal complaints the usual finding Singh 2022 Liu 2022. There is no established tolerable upper intake level.
What the safety record does not cover is duration. A compound taken for the purpose of slowing an aging process is a compound somebody intends to take for years, and the longest trial is four months. That is a real gap and it is the honest answer to 'is it safe long term' Dao 2026.
The theoretical concern is the mechanism itself. Mitophagy and autophagy are context-dependent: the same process that clears damaged organelles in a healthy cell can support survival of a stressed malignant one. No human data address this, and it is the reason anyone with an active cancer should treat this as an oncology conversation.
The interaction profile is thin because the metabolism is conjugative. There is no major cytochrome pathway to inhibit or induce. The plausible interactions are with other heavily glucuronidated compounds competing for the same conjugation capacity, which is a theoretical rather than a documented concern.
Who this is not established for. Pregnancy and lactation, with no data. Children, with no data. And anybody who could get the same effect from ellagitannin-containing food, if they happen to be a urolithin A producer — which is a real, cheap alternative for roughly two thirds of people and cannot currently be tested for Tomas-Barberan 2014. Nothing here is medical advice or diagnosis, and these statements have not been evaluated by the Food and Drug Administration.
Sources read for this page
- Singh A. 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. Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults. JAMA Netw Open 2022 · PMID 35050355
- Dao T. Effects of Urolithin A supplementation on muscle health outcomes in humans from randomized controlled trials. Front Nutr 2026 · PMID 42559151
- Whitfield J. Evaluating the Impact of Urolithin A Supplementation on Running Performance, Recovery, and Mitochondrial Biomarkers in Highly Trained Male Distance Runners. Sports Med 2025 · PMID 40839339
- Zhao H. Pharmacological Effects of Urolithin A and Its Role in Muscle Health and Performance: Current Knowledge and Prospects. Nutrients 2023 · PMID 37892516
- Tomas-Barberan FA, et al. Ellagic acid metabolism by human gut microbiota: consistent observation of three urolithin phenotypes in intervention trials, independent of food source, age, and health status.. Journal of Agricultural and Food Chemistry 2014 · PMID 24976365
How you would know if it worked
There is no blood test for this one. That is not a criticism — it is a fact about the effect, and it changes how you should judge it.
- What to watch: Muscle endurance in a fixed, repeatable test: reps to failure on one machine at one load, or a timed climb of the same stairs, measured before you start and again at eight and sixteen weeks. This is the rare product in the category with randomized human trials behind it, and endurance in middle-aged and older adults is what they measured — so copy that endpoint rather than inventing one.
- How long before it means anything: Sixteen weeks, because that is the length the trials ran, and eight at the absolute minimum. Nobody takes this and notices anything on Thursday, and expecting to is the most common reason people quit before the window they paid for.
- What will fool you: Your own training, which is the confound and also the point: exercise triggers mitophagy through the same pathway, so a new program started alongside the capsules will produce the improvement and take none of the blame. Keep the training fixed and change one thing. The other trap is buying pomegranate extract instead — most people lack the gut bacteria to convert the precursor, which is the entire reason the isolated molecule exists.
Run it one variable at a time. Starting three things in one week means a result you cannot attribute, which is the same as no result.
Urolithin A — safety & side effects
- Well tolerated in trials — side-effect rates comparable to placebo across several months.
- No established drug interactions.
- Long-term safety has not been characterized — the trials run weeks to months, not years. That is a real limit on what anyone can tell you about daily use for a decade. Among the better-studied things in this category, with real human trials rather than extrapolation from mice.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this against it with a pharmacist or doctor — pharmacists are underused and free.
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The full Supplement Vault — 371 products across 14 categories with clinical, correlative & theoretical evidence, plus my Thorne partner links — lives inside Skool alongside 278 peptides.
Join Skool — $10/mo →Bloodwork to run alongside Urolithin A
Baseline first, then again at 8–12 weeks.
| Marker | What it’s watching for |
|---|---|
| hs-CRP (High-Sensitivity C-Reactive Protein) | Inflammation baseline |
| Comprehensive Metabolic Panel (CMP) | Liver and kidney |
| Carnitine, Total and Free | Mitochondrial function — the mechanism actually being claimed |
The Longevity Baseline panel covers these in one order — 13 markers, $219.10 with the discount applied.
Check results you already have → · All 103 markers A–Z
Urolithin A — frequently asked questions
What is Urolithin A?
A gut-bacterial metabolite of pomegranate ellagitannins that switches on MITOPHAGY — your cells' quality-control system for mitochondria. Most people cannot make meaningful amounts of it themselves, which is the entire reason an isolated supplement exists.
What is the suggested dose of Urolithin A?
500 mg of Mitopure daily — every form, same dose. 2 softgels, or 1 powder stick, or 2 gummies. That's the trial dose and the label dose across all three, so choose on format rather than potency. Take with a meal. This is a general reference for education only — statements have not been evaluated by the FDA and this is not medical advice.
What are the researched benefits of Urolithin A?
Why mitophagy is the point. Mitochondria don't just fail quietly. A damaged one keeps consuming fuel while producing less ATP, and it leaks reactive oxygen species into the cell around it. So a broken mitochondrion isn't merely useless — it is actively damaging its neighborhood. Mitophagy is how the cell tags, dismantles and recycles them. That clearance rate falls with age, damaged mitochondria accumulate, and the result is the thing everyone describes identically: 'I train just as hard, I just don't recover the way I used to.'
Who is Urolithin A for?
Anyone over about 40 noticing recovery has slipped, and anyone building a longevity stack who wants the item with the strongest human evidence in it.
Where can I buy Urolithin A?
Coach Cam sources Urolithin A from vetted, top-rated brands on iHerb — use the buy link on this page.
Urolithin A inside a finished plan
One arm of 3 Protocol Blueprints, free to read in full.
What Urolithin A is used for
Urolithin A appears under 5 goals in the goal router.
Related Longevity & Antioxidants supplements
Where this goes next
Urolithin A is the autophagy arm of this plan. The page above is the free breakdown of one compound; the plan it belongs to — the dosing, the order to correct things in, the week-by-week schedule and what to retest — is a lesson inside Skool.