Extensive clinical trials have proven the beneficial effects of Evening Primrose when taken internally as a medicinal substance. However it is doubtful if the gamma-linolenic acid has much effect via topical application. This oil is very costly and it seems to have few advantages over cheaper refined vegetable oils. It is said to be good externally for: psoriasis, eczema and dry or prematurely aged skin.
Use as 10% additive.
A fine, light yellowish oil, with only a mild odour when fresh. However, it oxises very quickly and rancidity quickly develops. gamma-Linolenic acid is rapidly destroyed in the presence of oxygen.