Blue-Green Algae

Blue-green algae are a group of bacteria. They can be used as a source of protein, but contain no more protein than meat or milk.

Blue-green algae produce blue-green colored pigments and are high in protein, iron, and other minerals. They grow in saltwater and some large freshwater lakes. They have been used for food for several centuries in Mexico and some African countries. In the US, they've been sold in supplements since the late 1970s.

People use blue-green algae for treating high blood pressure and as a protein supplement. It's also used for high levels of cholesterol or other fats (lipids) in the blood, diabetes, obesity, and many other conditions. But there is no good scientific evidence to support these other uses.

Some blue-green algae products are grown under controlled conditions. Others are grown in a natural setting, where they're more likely to be contaminated. Only use products that have been tested and are free of contaminants such as heavy metals, liver toxins called microcystins, and harmful bacteria. Don't confuse blue-green algae with other algaes, like Ascophyllum nodosum, Ecklonia cava, Fucus Vesiculosis, or Laminaria.