As
Astaxanthin
AstaxanthinAntioxidant
Algae-derived carotenoid. Strong antioxidant in lab; visibly red-orange and easily oxidized in formulation.
What it does
Astaxanthin is one of the most potent antioxidants in lab assays — it sits in lipid membranes and quenches free radicals more efficiently than vitamin E or beta-carotene. The practical limit is the bright red-orange color (formulations turn pink) and the molecule's susceptibility to oxidation. Topical evidence is limited; the strongest evidence base is for oral supplementation rather than topical application.
The evidence, graded
moderateAntioxidants neutralize free radicals generated by the UV that gets through sunscreen. Layering an antioxidant serum under SPF compounds photoprotection.Wu 2011 · Clinical and Experimental Dermatology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
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