Estimated longevity benefit: +0.6 years. Evidence score: 100/100.
Astaxanthin is a xanthophyll carotenoid — the pigment that makes salmon, shrimp, and flamingos pink — produced by the microalgae Haematococcus pluvialis. Its membrane-spanning molecular structure makes it the most potent natural antioxidant known, with 6,000× greater free-radical quenching capacity than vitamin C. Multiple human RCTs confirm meaningful reversal of skin aging signs (wrinkles, elasticity, hydration) at 4–12 mg/day, with the foundational Tominaga et al. 2012 trial and a 2018 Nutrients comprehensive review as primary evidence.