Urolithin A — The Mitophagy Activator
Urolithin A (UA) is a gut-derived metabolite produced from ellagitannins (found in pomegranates, walnuts, and berries) by gut bacteria. It is the most potent known activator of mitophagy — the selective clearance of damaged mitochondria — and has demonstrated muscle-rejuvenating effects in human trials.
Mechanism of Action
UA activates the PINK1/Parkin mitophagy pathway, which tags damaged mitochondria for lysosomal degradation. This improves mitochondrial quality control, reduces reactive oxygen species, and enhances ATP production. UA also activates AMPK and reduces NF-κB-mediated inflammation.
Human Trial Evidence
A 2022 JAMA Network Open RCT (Liu et al.) showed 1,000 mg/day UA for 4 months significantly improved muscle strength, exercise performance, and mitochondrial biomarkers in middle-aged adults. A 2019 Nature Metabolism trial showed UA improved mitochondrial function in skeletal muscle of older adults.
Dosing Protocol
500–1,000 mg/day (Mitopure® brand used in clinical trials). Only ~40% of people produce UA from dietary ellagitannins due to gut microbiome variation — direct supplementation bypasses this. Best taken with food.
Safety & Contraindications
Excellent safety profile in all human trials. No serious adverse events at doses up to 2,000 mg/day. Urolithin A is a natural metabolite — well-tolerated across all age groups studied.