Evening Primrose Oil

Medically Reviewed by Melinda Ratini, MS, DO on May 13, 2021

Evening primrose is a plant that's native to Europe and North America. It has a long history of medicinal uses. Native Americans, for example, used its leaves, roots, and seedpods in preparations for hemorrhoids, bruises, wounds, and skin problems.

Evening primrose oil contains an omega-6 essential fatty acid that is necessary for good health. However, while there is some evidence that taking evening primrose oil supplements may benefit some health conditions, the study results are mixed.

Most of the studies have been small and further research is needed.

Why do people use evening primrose oil?

Evening primrose oil supplements usually come in capsule form. People take it to try to treat conditions such as:

  • Rheumatoid arthritis
  • Premenstrual syndrome (PMS)
  • Eczema, atopic dermatitis, and other skin conditions
  • Breast pain during menstruation
  • ADD
  • Asthma

Reviews of the available scientific evidence have found no reason to recommend evening primrose oil to help the symptoms of premenstrual syndrome or breast pain.

Current research does not show primrose oil to be helpful in eczema or atopic dermatitis. And some studies suggest that supplements that contain gamma-linolenic acid (GLA), including evening primrose oil, may be of some benefit to people with rheumatoid arthritis. But more research is needed before it could be recommended.

Evening primrose oil has also been used as a complementary treatment for some cancers. Again, evidence to support such use is lacking.


Can you get evening primrose oil naturally from foods?

GLA, thought to be the active ingredient in evening primrose oil, can be found in small amounts in a variety of food sources. However, it is most concentrated in plant oils such as evening primrose oil and borage oil. The doses used in most clinical trials would be hard to get from food sources.

What are the risks of taking evening primrose oil?

Most people will tolerate evening primrose oil without complications. But keep in mind that there have been reports of side effects such as:

Evening primrose oil may raise the risk of bleeding among people who take anticoagulant and antiplatelet medications. It may also raise the risk of seizures as well as serious nausea and vomiting for people taking a class of drugs known as phenothiazines. These drugs are used to treat schizophrenia and other psychotic disorders.

People should be especially cautious about taking evening primrose oil if they have:

  • Bleeding disorders
  • Seizure disorders such as epilepsy 
  • Mania

Also, people who take medication to lower blood pressure should be careful, because evening primrose oil may cause a further drop in pressure. Evening primrose oil may also interact with certain medicines used to treat depression.

Several other drug interactions have been noted. Evening primrose oil may cause seizures if used with anesthesia. Make sure you tell your doctor if you are taking this before you have any surgery.

Pregnant women should not take evening primrose oil because of the potential for complications.

Before taking evening primrose oil, or any other supplement, talk to your doctor about potential risks and drug interactions. Even so-called natural supplements should be used with caution.

The U.S. Food and Drug Administration (FDA) does regulate dietary supplements; however, it treats them like foods rather than medications. Unlike drug manufacturers, the makers of supplements don’t have to show their products are safe or effective before selling them on the market.

Show Sources


Natural Standard: "Evening Primrose Oil (Oenothera biennis L.)"

Georgetown University Medical Center: "Evening Primrose."

National Center for Complementary and Alternative Medicine: "Evening Primrose Oil."

Memorial Sloan-Kettering Cancer Center: "Evening Primrose Oil."

Natural Medicines Comprehensive Database: "Evening Primrose Oil."

Fan, Y-Y. The Journal of Nutrition, September 1998.

Mayo Clinic: "Evening Primrose."

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