The evening primrose is named for its night-blooming yellow flowers, but the plant's reputed therapeutic value is derived from the oil in its tiny seeds. Evening primrose oil is a source of gamma-linolenic acid, or GLA, an essential fatty acid abundant in most diets. The body uses GLA to make compounds that help fight inflammation.
Uses: The native North American plant has long been used in the United States and Europe to treat wounds and skin conditions, such as acne and eczema, though no firm evidence supports such uses. Today, supplement makers also market evening primrose oil for breast pain associated with premenstrual syndrome and menopausal flushing. Some companies also say that primrose oil can help treat heart disease, rheumatoid arthritis and a nervous condition associated with diabetes.
Dose: A few grams a day are recommended for most conditions. Evening primrose oil usually comes in 500-milligram softgels or capsules.
Precautions: Evening primrose oil is generally considered safe, though it may increase the likelihood of pregnancy complications and the risk of seizures in people prone to them. Some users may experience nausea or headaches.
Research: In several human studies, evening primrose oil was found to be no better than a placebo in treating symptoms of PMS and menopause. More studies have been conducted on GLA, but few of these have produced conclusive results and several have been criticized for poor study design.
Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.
-- Elena Conis