Castor oil is taken from the bean of the castor plant and is rich in ricinoleic acid which has a powerful therapeutic value. It has a low molecular weight, which means it is absorbed readily into skin and hair, providing nourishment and moisturizing effects. It is low comedogenic (1 out of 5) and is non-irritating. It has acanthotic activity, meaning that it can help increase skin thickness. Ricinoleic acid is an interesting fatty acid with its chemical structure also acting as a humectant, meaning that it attracts water to the hair and skin.
Castor oil contains some phytosterols in the form of ß-sitosterol, campesterol, and stigmasterol, which offer some anti-inflammatory and itch reducing properties. The ricinoleic acid found in castor oil gives it astringent, analgesic, anti-microbial, anti-bacterial, and possibly anti-fungal properties making it an ideal addition to any cleansing oil blend.