Mucuna pruriens - otherwise known as Velevet Bean, Cowhage, Cowitch and even 'Mad Bean' - is a climbing plant that can be found in tropical regions of Africa, South Asia and the Caribbean. The plant has a whole range of uses in various traditional medicinal practices, in modern herbal supplements, and is also sometimes used as a fallow crop to feed livestock.
Many of the plant's colloquial names (such as cowitch) refer to the intense irritation and itching that is experienced if parts of the plant - in particular the seed pods and young leaves - are allowed to come into contact with skin. Others refer to the psychoactive properties of the plant's seeds, which contain a chemical called levadopa - a precursor to the dopamine that our brains use as a messenger and reward chemical.
As well as containing a relatively high concentration of levadopa, Mucuna pruriens extract contains several other compounds that have an effect upon mood and perception, including serotonin. It is thought that the plant could be useful in the fight against depression and other mood disorders.
Mucuna pruriens is not by itself hugely popular as a supplement but is more usually added as an ingredient to blends of other herbal extract developed for a range of different purposes. It's subtle effects upon brain chemistry and mood make it an important ingredient in a range of products, from anti-premature ejaculation pills such as Ejacutrol, through semen volumizers such as Spermomax, to eye-health supplements such as Eyefine.