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Mitochondria & energyEvidence grade: Human trials

Urolithin A

Gut-microbiome metabolite of ellagitannins

A gut-derived metabolite that triggers mitophagy — the clearance of damaged mitochondria — with completed human trials.

Last reviewed · 1 references

How it works

Urolithin A is produced when gut bacteria metabolise ellagitannins from pomegranate, walnuts and berries. Only around 40% of people carry the microbiome to make meaningful amounts. It induces mitophagy, the selective recycling of damaged mitochondria, which is a distinct mechanism from making mitochondria run better or making more of them.

Human trials. Tested in controlled human trials. Still read the sample sizes — many are small.

What the research reports

  • Randomised human trials showing improved muscle endurance in middle-aged and older adults
  • Confirmed induction of mitophagy biomarkers in humans
  • Well tolerated at trial doses

What it has not been shown to do

  • No cognitive or mood endpoints tested in humans
  • Effect sizes on function are modest

Dosing reference

Human trials commonly use 500–1000 mg/day orally.

Calculate my dose for Urolithin A
Routes studied
Oral
Half-life
Extended by glucuronidation; steady state reached over days
Cycle length in the literature
Trials ran 4 months of continuous daily dosing

Working out a draw volume from a vial? Use the free reconstitution calculator.

Side effects and contraindications

Reported side effects

  • Generally well tolerated; occasional GI upset

Do not use if

  • Pregnancy and breastfeeding — not studied

The practice that shares the mechanism

Mitophagy is also triggered by fasting and by exercise. Urolithin A is one of the few compounds here where the human trial data is solid enough that it can stand next to the practices rather than behind them.

What amplifies it

  • Fasting windows independently induce mitophagy
  • Deep sleep, when a large share of cellular housekeeping occurs
  • Eating the precursor foods only works if your microbiome converts them

Mechanism hubs

Stacks that include it

Common questions

Sources & evidence notes

Evidence grade: Human trials1 source · 0 human · 0 animal · reviewed 1 Jun 2026

Tested in controlled human trials. Still read the sample sizes — many are small.

Confidence score 3/100

Preliminary

Mechanism only. Nothing here establishes that a person would feel anything.

Search all sourcesExports the 1 source currently shown.
  1. 1.

    Cell Reports Medicine, 2022 · Source (opens in a new tab)

    In vitroLimited gradeCells or tissue in a dish. Tells you about mechanism, not about outcomes.