Common Names: evening primrose oil, EPO

Latin Names: Oenothera biennis

Background

Evening primrose is a plant native to North and South America that also grows throughout Europe and parts of Asia. It has yellow flowers that open at sunset and close during the day. The oil from evening primrose seeds contains omega-6 fatty acids, including gamma-linolenic acid (GLA).

Native Americans made poultices from the evening primrose plant for bruises and wounds and used its stem and leaf juices as topical remedies for skin inflammations. The leaves were taken orally for gastrointestinal complaints and sore throats. In the 17th century, evening primrose oil became a popular folk remedy in Europe, where it was known as “King’s cure-all.”

Today, evening primrose oil dietary supplements are promoted for atopic dermatitis (a type of eczema), rheumatoid arthritis, premenstrual syndrome (PMS), breast pain, menopause symptoms, and other conditions. Evening primrose oil may also be included in products that are applied to the skin.

How Much Do We Know?

Many studies in people have evaluated evening primrose oil for atopic dermatitis or breast pain. Smaller numbers of studies have evaluated it for other health conditions.

What Have We Learned?

There’s not enough evidence to support the use of evening primrose oil for any health condition.

Evening primrose oil, taken orally (by mouth), has not been shown to be helpful for relieving symptoms of atopic dermatitis.

Studies of evening primrose oil for breast pain have not found it to be more effective than a placebo (an inactive substance).

There’s insufficient evidence to show whether evening primrose oil is helpful for other conditions, such as PMS and menopause symptoms.

What Do We Know About Safety?

Evening primrose oil may be safe for use during pregnancy and while breastfeeding, but the evidence is not conclusive.

Evening primrose oil is generally well tolerated. The most common side effects are temporary gastrointestinal symptoms such as abdominal pain, fullness, or nausea.

Evening primrose oil may increase the effects of the HIV medicine lopinavir. As with all dietary supplements, talk with your health care provider before taking evening primrose oil if you are taking any kind of medicine.

Information provided by the National Center for Complementary and Integrative Health