Castor oil is a vegetable oil and it comes from the castor oil plant (Ricinus communis). The seed is known popularly as the “castor bean,” but it isn’t really a bean. Castor oil plants grow naturally in Eastern Africa, India, the southeastern Mediterranean Basin, and the Caribbean. It’s grown as an ornamental flowering plant in some places.
The “bean” or seed of the castor oil plant is said to contain 40 to 60% oil, and that oil is known to be a source of the toxic protein ricin, but heating it up during the extraction process deactivates it. Harvesters have to be careful because compounds from the plant itself can lead to nerve damage.
Castor oil isn’t just recommended for hair growth on your head. Varieties without additives have also become popular for careful use on eyebrows and eye lashes.
Nowadays castor oil has become extremely popular for hair, in particular the varieties being exported from Caribbean islands. It seals in moisture, and has been said to stimulate the scalp and assist in hair growth. The grade of castor oil used for hair is not recommended for internal use.