Tamanu oil is a treatment long used in Polynesia and Southeast Asia for the improvement of hair and skin health. The oil which is extracted from the nut of the laurelwood (Calophyllum inophyllum) tree is sometimes used on the face or elsewhere on the body for conditions such as acne, psoriasis, rosacea, keloids, and other scars. Tamanu oil has properties that help moisturize your skin. Because it is rich in fatty acids, the oil locks moisture in by acting as a barrier. Researchers have also found that tamanu oil contains calophyllolide (a substance known to possess anti-inflammatory properties) and delta-tocotrienol (a form of vitamin E), as well as a number of antioxidants. So far, research on the health effects of tamanu oil has been limited. Most studies are performed in labs on cells, rather than on human subjects. Study results have been inconsistent and don't always support the use of the oil for any skin or hair condition.