Haematococcus pluvialis is a microalga that yields astaxanthin, a carotenoid antioxidant. People take it to guard skin against oxidative stress from UV light and to support recovery after exercise.
Take astaxanthin with a meal that includes fat to boost absorption. Doses differ by supplement form, so follow the label instructions.
Astaxanthin might have antiplatelet effects. If you take blood thinners like warfarin, aspirin, or clopidogrel, talk to a healthcare provider before using it.