Spirulina is a blue-green alga that uses atmospheric nitrogen to make proteins. It has an enormous production capacity, capable of generating twenty times the amount of protein as that of soybeans on an equal land surface. It thrives in hot sunny climates and alkaline waters in many parts of the world, and has been traditionally eaten in the Lake Chad area of West Africa and Mexico.

Spirulina algae contain nutrient concentrations that are not found in any other single plant food. They have gamma-linolenic acid (GLA), linoleic acid (LA) and arachidonic acid (AA), large amounts of vitamin B12 of particular value to vegetarians, the essential amino acids, the nucleic acids DNA and RNA, 60 to 70 percent protein, and a high iron content. At the same time they contain chlorophyll and phycocyanin, a blue pigment found only in blue-green algae, which increased the survival rate of laboratory animals with liver cancer.

Spirulina also curbs the appetite and can help a hypoglycemic person by providing a snack between meals, the high protein of which helps stabilize the blood sugar. Equally It helps mineral absorption, reduces cholesterol, and strengthens the immune system.

Usually non-toxic, but allergic reactions are possible.