Spirulina is a blue-green algae, and is believed to be one of the oldest life forms on Earth.

First used by the Aztecs as an endurance-booster, spirulina is considered a superfood — an all-in-one source of nutrients including protein levels comparable to eggs.

The Aztecs also used spirulina to treat various diseases, and legends say that the kingdom’s messengers used the algae to sustain their marathon runs. Modern research supports many of the alleged benefits of taking spirulina, and continues to study its potential for treating health concerns.

Spirulina has a bitter taste, so people often mix it with yogurts, juices, and smoothies to improve its flavor. Spirulina is commonly available as a supplement at health food stores.