Evening primrose oil: A natural source of essential fatty acids (EFOs). Last Editorial Review: 7/1/2016 Take the Vitamins and Supplements Quiz! Take the Happiness Quiz! 15 Immune Boosting Foods! Health Solutions From Our Sponsors Health in Young Adults Open Heart Alternatives Travelers Diarrhea 21st Century Cures How to Save a Life Care for Aortic Stenosis? Nutritious Smoothies Family Wellness Consider Clinical Trials Bent Fingers? Delicious Alternative to Milk Tips to Beat Heartburn Treat Type 2 Diabetes Rehabilitation Services What is TAVR?