Chlorella is a single-celled, green freshwater algae (1Trusted Source).
There are over 30 different species, but two types — Chlorella vulgaris and Chlorella pyrenoidosa — are most commonly used in research (2Trusted Source).
Because chlorella has a hard cell wall that humans cannot digest, you must take it as a supplement to reap its benefits (3).
It’s available in capsule, tablet, powder and extract form (3).
In addition to being used as a nutritional supplement, chlorella is also used as a biodiesel fuel (4).
Interestingly, studies indicate it can have many health benefits. Here are 9 of them.