What is Microcystin? Microcystin is a toxin produced naturally in cyanobacteria, which are also known as blue-green algae. It is a type of cyanotoxin and can have several harmful effects on human health. Most Microcystins are hepatotoxins, meaning they affect the liver. However, not all blue-green algae species produce microcystin — and microcystin is only...Continue Reading