# Astaxanthin

Astaxanthin is a red-pink pigment (a ketocarotenoid). It is made mainly by a microalga (Haematococcus pluvialis). It then travels up the food chain into crustaceans, salmon, and trout, giving them their color. Its structure is special. It has a long polyene chain with carbonyl and hydroxyl groups on both rings. That lets it stretch across a full cell membrane and neutralize singlet oxygen and free radicals. In lab tests, it quenches singlet oxygen better than many other carotenoids, including β-carotene. And unlike some antioxidants, it does not flip into a pro-oxidant at high doses. Its proposed longevity mechanisms include switching on Nrf2, blocking NF-κB, protecting mitochondria, and tuning inflammatory signals. Rodent studies show better oxidative stress, immunity, and some heart markers. Human trials are small and short. They report modest effects on fat-oxidation markers, skin aging, exercise muscle damage, and inflammation. One nuance: synthetic astaxanthin (common in fish farming) differs from natural algal forms in chemistry. That may change how well you absorb it. Evidence for a direct human longevity benefit is still preliminary.

## Sources

- Guerin M, Huntley ME, Olaizola M. (2003). Haematococcus astaxanthin: applications for human health and nutrition. Trends in Biotechnology. https://doi.org/10.1016/S0167-7799(03)00078-7
- Choi HD, Kim JH, Chang MJ, Kyu-Youn Y, Shin WG. (2011). Effects of astaxanthin on oxidative stress in overweight and obese adults. Phytotherapy Research. https://doi.org/10.1002/ptr.3494

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_Canonical: https://longevity-switzerland.com/en/glossary/astaxanthin · Part of Longevity Cities · Updated 2026-06-22_