The oil coming from the seeds of the nice, little, yellow-flowered plant called Evening Primrose. Similar to other plant oils, it's loaded with nourishing and moisturizing fatty acids. It's a very rich source of linoleic acid (66-76%), and also contains the soothing and healing superstar fatty acid, gamma-linolenic acid (aka GLA, 7-12%) (Btw, the richest known source of GLA is the borage oil, but evening primrose still counts as a very good source of it). It also contains oleic acid, but not too much around 6-15%.
Since the 1980's, EPO is a well-known food supplement and there are quite a lot of studies examining what happens if you take it orally. It seems to be helpful with a bunch of things: atopic dermatitis, dry eyes, brittle nails, sunburn and even acne.
As for the skin, it's a great hydrating plant oil, that can also reduce inflammation and irritation. It's a superb healing agent that can truly help dry skin, not just on the surface by covering it (and not letting water to evaporate) but by initiating structural changes within the skin. If that's not enough, it also helps skin cell regeneration.
All in all, a real goodie especially for dry, easily irritated skin.
- Leslie Baumann, MD, Cosmetic Dermatology, 2nd edition, Evening Primrose Oil - p55