What it is
Regulatory status: dietary supplement (US); proposed novel-food ingredient (EU/UK, not authorised as of this review — see section 7). Not a medication. Not a device
At a glance
What it is, why people use it, the evidence, and what to know before trying it.
Why people use it
- Activates mitophagy / improves mitochondrial function.
- Improves muscle endurance (fatigue resistance).
- Improves muscle strength.
- Improves VO2 / aerobic capacity / exercise performance.
- Lowers inflammation (CRP and related cytokines).
- Improves aging biomarkers / slows aging.
- Works regardless of gut metabotype (direct UA vs ellagitannin conversion).
- Rejuvenates aging immune cells.
- Safe at 500-1000 mg/day.
Evidence at a glance
Urolithin A is a real, bioavailable, synthetic postbiotic. Direct 500-1000 mg/day matches the human trial doses and clearly beats pomegranate juice for plasma exposure, because only a minority of people convert ellagitannins well (Singh 2022 Eur J Clin Nutr: 12% detectable at baseline, ~40% high converters at 24 h). Human RCTs, almost all Amazentis-funded and 4 weeks to 4 months long, show a mitochondrial **molecular signature**, a modest CRP/acylcarnitine signal, and mixed, often secondary, muscle findings: hamstring strength ~10-12% vs a declining placebo in one middle-aged trial (Singh 2022); contractions-to-fatigue at 2 months but not a significant 4-month or ATP or 6MWT win in older adults (Liu 2022). The ATLAS primary endpoint (peak power) failed. The only pooled functional meta-analysis (6MWT, two trials) is +17 m and not significant (Dao 2026). Immune-phenotype and athlete-performance signals exist but are small-n and short. Safety at 500-1000 mg for up to 4 months looks clean; EU/UK novel-food authorisation is still pending.