Inositol is considered a vitaminoid, a vitamin-like substance that was identified about 100 years ago in the urine of diabetics. Today it is classified as a complex of B vitamins. Inositol is a (hexavalent) alcohol and occurs both in plants (as phytic acid) and in animals (as myo-inositol). Inositol is present in practically all tissues of the human body. It is particularly highly concentrated in the brain, kidneys, liver, spleen and testicles. Animal experiments have shown that a lack of inositol can lead to growth disorders, hair loss and fatty liver.