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Evening Primrose Oil

Evening primrose flower
© Steven Foster

Common Names: evening primrose oil, EPO

Latin Names: Oenothera biennis


  • 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 is probably safe for most adults. Less is known about its safety for children.
  • 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.

Keep in Mind

  • Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

For More Information

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The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

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Office of Dietary Supplements (ODS), National Institutes of Health (NIH)

ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need To Know) and fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements).


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Key References

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NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: August 2020