As an antioxidant, in general, manufacturers recommend taking 4-8 milligrams of astaxanthin by mouth 2-3 times daily with meals.
Clinical evidence is lacking.
For dyspepsia, 40 milligrams of astaxanthin has been taken by mouth daily in divided doses for four weeks.
For exercise capacity, the manufacturers of Xanthin recommend taking one capsule by mouth (each containing eight milligrams of astaxanthin) before and after physical activity.
Four milligrams of astaxanthin has also been taken by mouth in the morning with food.