Astaxanthin is renowned for its powerful antioxidant qualities

H. pluvialis microalgae, whose cells are seen here under a microscope, is used to make astaxanthin supplements due to their naturally-high bioavailability of this antioxidant. — Wikimedia Commons

There's a reason why astaxanthin is one of the most popular antioxidant supplements right now.

Part of the carotenoids group, astaxanthin is reddish in colour and packed with anti-inflammatory properties and other health benefits.