Urolithin A
UA · Uro-A · Mitopure · 3 · 8-dihydroxy-6H-dibenzo[b · d]pyran-6-one
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At a glance
Overview
Urolithin A has quietly become one of the most evidence-backed compounds in the longevity and recovery toolkit — not because it promises a dramatic acute effect, but because it does something no other widely available supplement reliably does: trigger mitophagy, the selective clearance of damaged mitochondria. For physique-focused users running heavy training volume, AAS cycles, or aggressive cuts, mitochondrial strain is the silent tax on recovery. UA targets that tax directly.
The reason it's generated real traction (rather than the usual nootropic churn) is that it has human muscle biopsy data. A 4-month RCT in middle-aged adults showed measurable improvements in muscle endurance and mitochondrial health markers at 500 mg and 1000 mg daily, and a 28-day trial confirmed the compound actually reaches skeletal muscle and shifts gene-expression signatures toward a younger mitochondrial phenotype. For most people, the kicker is that you can't get there through diet — roughly 60–70% of adults lack the gut bacteria needed to convert dietary ellagitannins into UA, which is why eating pomegranates doesn't replicate the effect.
"Urolithin A supplementation for 4 months significantly improved muscle endurance and mitochondrial health markers in both hand and leg muscles compared to placebo." — Singh A, D'Amico D, Andreux PA, et al., Cell Reports Medicine (2022)
This is a chronic-use, slow-burn compound — not something you feel in the first week, and not something you cycle. The community has settled on 500–1000 mg once daily with a fat-containing meal, run continuously for at least 8–16 weeks before judging effect. Below we cover the mechanism in more detail, the dose ladder, use-case protocols (endurance stacks, on-cycle organ support, masters-lifter sarcopenia protocols, and longevity stacking with NAD precursors and rapamycin), the side-effect profile (which is notably clean), sourcing notes on Mitopure vs bulk powder, and the pitfalls that make people quit too early and conclude "nothing happened."
How Urolithin A works
Urolithin A isn't a stimulant, a hormone, or a direct anabolic. It's a mitochondrial housekeeping compound — a gut-microbial metabolite of ellagitannins that, once absorbed, triggers the cell's own quality-control machinery to clear out damaged mitochondria and rebuild the pool with younger, more efficient ones. The practical read: better endurance, faster between-session recovery, and a gradual fatigue-resistance shift over 2–4 months of chronic dosing.
Mitophagy via PINK1/Parkin#
The headline mechanism. UA selectively induces mitophagy — the autophagic clearance of damaged or dysfunctional mitochondria — primarily through the PINK1/Parkin pathway. Damaged mitochondria lose membrane potential, PINK1 accumulates on the outer membrane, Parkin is recruited, ubiquitin tags are applied, and the organelle gets shuttled into an autophagosome for degradation. UA dose-dependently tips this cycle toward activation, which is unusual — most interventions drive general autophagy (rapamycin, fasting, sirtuin activators), whereas UA targets the mitochondrial subset specifically.
"Urolithin A treatment induced mitophagy in genetically diverse organisms and increased lifespan and muscle function across species, establishing UA as a potent mitophagy inducer." — Ryu D, Mouchiroud L, Andreux PA, et al. Nature Medicine, 2016
For lifters and endurance athletes, this matters because skeletal muscle mitochondrial damage accumulates with training volume and age. Clearing the damaged pool is the prerequisite for biogenesis to actually produce a net gain in oxidative capacity.
Secondary Mitochondrial Biogenesis#
Once the damaged mitochondria are cleared, UA supplementation is associated with upregulation of PGC-1α and TFAM — the master regulators of mitochondrial biogenesis — along with shifts in plasma acylcarnitines consistent with improved fatty-acid oxidation. This is the "rebuild" half of the cycle: new, functional mitochondria replacing the ones tagged for disposal.
"Urolithin A was well tolerated and induced a molecular signature consistent with improved mitochondrial and cellular health in both plasma and muscle biopsies after 28 days of supplementation." — Andreux PA, Blanco-Bose W, Ryu D, et al. Nature Metabolism, 2019
The Andreux trial is the key translational result — they took actual muscle biopsies and showed UA reached the target tissue and shifted the gene-expression signature toward a younger, more oxidatively competent phenotype. Not a surrogate biomarker in plasma, but the muscle itself.
Skeletal Muscle Performance#
At the functional level, the mitophagy → biogenesis cycle translates into measurable improvements in muscle endurance, particularly in aging or mitochondrially-stressed tissue. The 4-month RCT in middle-aged adults is the cleanest human efficacy data we have, and it separates UA from most longevity compounds that only have biomarker evidence:
"Urolithin A supplementation for 4 months significantly improved muscle endurance and mitochondrial health markers in both hand and leg muscles compared to placebo." — Singh A, D'Amico D, Andreux PA, et al. Cell Reports Medicine, 2022
The effect is endurance and fatigue-resistance, not hypertrophy or strength. UA is not going to add lean mass or move your 1RM. What it does is let you recover faster between high-volume sessions and maintain output on set 4 and set 5 the way you did on set 1. In preclinical disease models (Duchenne muscular dystrophy), the same mechanism preserved force output and mitochondrial function — evidence the pathway is robust, not a biomarker artifact (Luan 2021).
Anti-Inflammatory and AhR Signalling#
UA is a partial aryl hydrocarbon receptor (AhR) agonist at physiological concentrations, and it suppresses NF-κB signalling in macrophages and muscle. This is the likely mechanism behind the reduced inflammatory-cytokine output seen in preclinical and early clinical work, and it contributes to the recovery profile — less systemic inflammation between training sessions means the rebuild happens faster.
There's also early evidence for T-cell and NK-cell rejuvenation in aged immune systems, which is the basis for ongoing immune-aging trials. For the physique-focused user, this is a background effect rather than a primary reason to run it.
The Microbiome Problem (Why You Can't Just Eat Pomegranate)#
The mechanism that makes direct UA supplementation necessary rather than optional:
"Only about 30–40% of adults are able to convert ellagitannins to urolithin A due to gut microbiota composition, making direct UA supplementation necessary for most individuals." — Xu H, Lv D, Guan Y, Journal of Agricultural and Food Chemistry, 2025
Dietary ellagitannins from pomegranate, walnuts, and berries are not UA — they're the precursor. Conversion requires specific gut bacteria (Gordonibacter, Enterocloster) that roughly 60% of adults don't host in sufficient numbers. Eating the fruit is fine food, but it's not a reliable delivery vehicle. Direct oral UA (Mitopure or bulk synthetic) bypasses the lottery entirely and puts the conjugated metabolite into plasma regardless of your microbiome composition. This is why the supplement category exists at all.
Protocol
| Level | Dose | Frequency | Notes |
|---|---|---|---|
| Low | 250–500 mg | Once daily | Documented entry-level range |
| Mid | 500–1000 mg | Once daily | Most commonly studied range |
| High | 1000–1000 mg | Once daily | Once daily with breakfast or the first fat-containing meal. No loading phase, no cycling — this is a chronic-use compound. Allow 8–16 weeks before judging effect. |
Cycle length & outcomes
Documented cycle
8–52 weeks
Plateau after
16 wks
Urolithin A is a chronic-use compound — no loading phase, no cycling, no washout. It is taken daily, with food, and is run long enough for mitochondrial turnover to actually play out. The trials that showed endpoint movement ran 16 weeks, so anything shorter than 8 weeks is functionally a pilot, not a protocol.
| Goal | Cycle Length | Daily Dose |
|---|---|---|
| Endurance / recovery (high-volume training) | 12–16 weeks minimum, often continuous | 500 mg |
| Masters / sarcopenia protocol (40+) | Continuous (6–12 months+) | 1000 mg |
| On-cycle organ / mitochondrial support alongside AAS | Duration of cycle + 4 weeks PCT | 500 mg |
| Longevity / healthspan stack | Continuous | 250–500 mg |
| Post-cut or post-illness mitochondrial recovery | 8–12 weeks | 500 mg |
| Clinical trial-matched dosing | 16 weeks → reassess | 1000 mg |
Onset timing. Don't expect an acute "feel." The dose-ranging work showed plasma and muscle-biopsy shifts within 28 days at 500–1000 mg/day, but those are molecular readouts — gene-expression signatures and acylcarnitine patterns, not something you notice in the gym.
"Urolithin A was well tolerated and induced a molecular signature consistent with improved mitochondrial and cellular health in both plasma and muscle biopsies after 28 days of supplementation." — Andreux et al., Nature Metabolism (2019)
Perceptible fatigue-resistance and recovery changes generally show up between weeks 6 and 10, and the endpoints that moved in the longer RCT did so at the 4-month mark:
"Urolithin A supplementation for 4 months significantly improved muscle endurance and mitochondrial health markers in both hand and leg muscles compared to placebo." — Singh et al., Cell Reports Medicine (2022)
If you quit at week 4 because "nothing happened," you stopped before the window where endpoints actually move. This is the single most common mistake with this compound.
No loading, no taper. UA is non-hormonal, has no HPTA activity, and does not require PCT. Stopping abruptly produces no rebound — mitochondrial quality simply drifts back toward baseline over weeks to months as the mitophagy stimulus is withdrawn. Some users cycle 4 months on / 1 month off for cost reasons; there's no pharmacological rationale for it, but no harm either.
Dosing mechanics. Once daily, with breakfast or the first fat-containing meal of the day. Fasted dosing meaningfully reduces exposure — don't bother dry-dosing capsules on an empty stomach. Splitting the dose AM/PM is fine but unnecessary given the ~17–22 hour half-life of the glucuronide conjugates.
Bloodwork cadence. UA itself doesn't require monitoring — it doesn't move lipids, liver enzymes, hematocrit, or endocrine markers, and there's no established interaction with standard panels. If you're stacking it with AAS, run your normal on-cycle bloodwork (lipids, liver, hematocrit, E2, full hormone panel) on your usual schedule; UA is additive, not confounding. For long-term chronic use as part of a longevity stack, a standard annual metabolic panel is sufficient.
Why direct supplementation, not dietary. The microbiome lottery is real and it's the reason this compound exists as a product at all:
"Only about 30–40% of adults are able to convert ellagitannins to urolithin A due to gut microbiota composition, making direct UA supplementation necessary for most individuals." — Xu et al., J. Agric. Food Chem. (2025)
Eating pomegranates and walnuts is good food behavior, but for 60%+ of adults it delivers near-zero circulating UA. If the mitophagy signal is desired, direct supplementation is necessary.
Stacking cadence. UA layers cleanly with creatine (5 g daily), CoQ10 (100–200 mg), PQQ (20 mg), NAD precursors (NMN or NR), omega-3, and vitamin D — none of these interact pharmacologically, and the mitochondrial-support logic is complementary rather than redundant. In a broader longevity stack with rapamycin (pulsed weekly) or metformin/berberine, UA occupies the mitophagy-specific lever — rapamycin drives bulk autophagy, UA drives selective mitochondrial autophagy via PINK1/Parkin. Different steps, same direction.
Run it long, run it with food, and judge it at the 3–4 month mark — not the 3–4 week mark.
Risks & mistakes
Common (most users)#
- Mild GI upset (bloating, loose stool, occasional nausea) — the most frequently reported effect, usually at the 1000 mg dose. Take with a fat-containing meal (breakfast works well), split the dose if needed (500 mg AM / 500 mg PM), and it typically resolves within the first week. If it persists, drop to 500 mg — you lose very little effect size.
- No perceptible acute "feel" — not technically a side effect, but worth flagging because it drives people to quit early. UA is not stimulatory. If you're expecting a kick, you'll conclude "nothing is happening" and stop at week 4, well before the endurance/recovery signal actually shows up (weeks 6–16 in the trials).
- Dark-colored urine — occasional, benign, from the conjugated metabolites. No action needed.
"Urolithin A was well tolerated and induced a molecular signature consistent with improved mitochondrial and cellular health in both plasma and muscle biopsies after 28 days of supplementation." — Andreux et al., Nature Metabolism (2019)
Uncommon (dose-dependent or individual)#
- Persistent GI discomfort at 1000 mg — a small minority don't acclimate. Drop to 500 mg; the dose-response curve plateaus, so you're not giving up much.
- Mild headache in the first 1–2 weeks — reported anecdotally, resolves on its own. Hydration and food-timing usually handle it.
- No movement in standard bloodwork — UA does not shift lipids, liver enzymes, glucose, or hematologic markers at clinical doses over 4 months. If something moves on your panel, look at the rest of your stack (AAS, orals, other supplements) before blaming UA.
"Urolithin A supplementation for 4 months significantly improved muscle endurance and mitochondrial health markers in both hand and leg muscles compared to placebo." — Singh et al., Cell Reports Medicine (2022)
Rare but serious#
No serious adverse events have been reported in the published human trials (doses up to 1000 mg/day for 4 months, Andreux 2019; Singh 2022). The theoretical concerns worth knowing:
- Allergic reaction — rash, itching, swelling. Stop immediately. Rare but possible with any novel compound.
- Unexplained severe GI symptoms (persistent vomiting, sustained diarrhea, abdominal pain) — stop and reassess; almost certainly a contamination or vendor-quality issue rather than UA itself, especially with bulk research-chemical sourcing.
- Long-term (>1 year) human safety data is still being accumulated. "No signal to 4 months" is not the same as "proven safe over a decade." This is the honest state of the literature.
Hard contraindications#
- Pregnancy and lactation — not studied, avoid. This is non-negotiable regardless of how clean the short-term profile looks.
- Active malignancy on therapy — UA has mixed preclinical signals (anti-tumor in some models, pro-survival in others). Do not freelance UA alongside active cancer treatment. Coordinate with your oncology team or skip it until treatment is complete.
- Known hypersensitivity to urolithins or ellagitannin metabolites — stop and don't restart.
Gender, endocrine, and PCT considerations#
UA is non-hormonal. It has no androgenic, estrogenic, progestogenic, or HPTA activity. Specifically:
- Women use identical dosing to men (500–1000 mg/day). No virilization risk, no menstrual disruption reported. Avoid during pregnancy and lactation.
- No PCT required or beneficial — UA does not suppress LH/FSH or testosterone and does not require recovery support.
- No interaction with AAS, SARMs, or peptides at the endocrine level. Runs cleanly alongside a cycle as organ/mitochondrial support, and continues unchanged through PCT.
- Semen quality / fertility — no signal either direction in the human data. Not an issue for men trying to conceive.
This is one of the cleaner compounds in the longevity category — the realistic downside is that it's expensive and slow to show effects, not that it's going to hurt you.
Stack & combine
Multipliers applied when these compounds run together. Values > 1 indicate a bonus on that axis. Tap a partner to expand the mechanism.
| Partner | Type | Lean | Fat loss | Recovery |
|---|---|---|---|---|
| synergistic | ×1.10 | ×1.13 | ×1.22 | |
| synergistic | ×1.15 | ×1.10 | ×1.22 | |
| synergistic | ×1.18 | ×1.14 | ×1.22 |
Featured in stacks1 curated protocol include Urolithin A
FAQ — Urolithin A
Research & citations
5 studies cited on this page.
Conclusion
Urolithin A stands out as an evidence-backed, low-risk way to target mitochondrial health, endurance, and recovery — perfect for anyone building a longevity, recovery, or "mitochondrial support" stack.
Key takeaways:
- Dose: 500–1000 mg oral, once-daily with a fat-containing meal for optimal absorption
- Protocol: Continuous use, 8–16 weeks minimum before judging results; no need to cycle or pulse
- Route: Oral capsules/softgels — no injectable forms
- Stacking: Pairs well with creatine, NMN/NR, CoQ10/PQQ, and TUDCA or NAC if running organ support on-cycle
- Headline benefit: Gradual improvements in muscle endurance, recovery, and cellular health via mitophagy — not a stimulant or acute ergogenic
- Side effects: Very mild (occasional GI at higher doses); safety profile in published trials is excellent
If you're after sustainable improvements in recovery and fatigue-resistance, and you're building a foundation for long-term performance, Urolithin A is a smart, clinically-validated addition to the toolkit.