Urolithin A
A postbiotic that triggers mitophagy (recycling of damaged mitochondria). Human RCTs show improved mitochondrial biomarkers and modest muscle-endurance gains — but the lifespan claim comes from worms, and roughly 60–70 % of people can't make it from food themselves.
How it works
Urolithin A is not present in any food directly: specific gut bacteria (e.g. Gordonibacter) convert ellagitannins from pomegranate, walnuts, and berries into it — hence postbiotic. Its best-documented action is mitophagy: the selective clearing and recycling of damaged mitochondria. In preclinical models this restores mitochondrial quality and muscle function. In humans, oral Urolithin A is bioavailable and shifts molecular markers of mitochondrial health (lower acylcarnitines and ceramides, upregulated mitophagy and mitochondrial genes in skeletal muscle).
Dosage
500–1000 mg/day, any time. Note: most documented effects come from supplementation, because only about 30–40 % of people host the gut bacteria needed to make Urolithin A from pomegranate, walnuts, and berries themselves.
Considerations
Human RCTs are solid for what they actually show: better mitochondrial biomarkers, modestly improved muscle endurance, and lower inflammation (CRP). Andreux 2019 established safety and a molecular mitochondrial fingerprint, Singh 2022 found roughly 10–12 % more muscle strength (as proof-of-concept), Liu 2022 improved muscle endurance plus lower CRP, acylcarnitine, and ceramide levels. Urolithin A (Mitopure) also holds an FDA 'no questions' GRAS status — a food-safety clearance, not an efficacy approval. Three things need honest framing: the plus 45 % lifespan extension is from worms (C. elegans), not humans or mammals, and both pivotal human RCTs missed their primary functional endpoints (6-minute walk, maximal ATP production). About 60–70 % of people cannot make it from food and therefore need the standardized supplement — pomegranate extracts do not reliably deliver Urolithin A. The effective 500–1000 mg/day doses make it one of the more expensive single supplements. Manufacturer Amazentis/Timeline has a commercial interest, so company-involved studies (such as the 2025 immune finding) are best read as hypothesis-generating.
