evening primrose oil

Evening primrose oil is pressed from the seeds of the evening primrose (Oenothera biennis), a flowering plant native to North and South America. The oil is rich in omega-6 fatty acids, notably gamma-linolenic acid (GLA), and that GLA content is the main reason it is marketed as a dietary supplement.

According to NCCIH, there is not enough evidence to support using evening primrose oil for any health condition. Taken by mouth, it has not been found to ease the symptoms of atopic dermatitis, and for breast pain it appears to work no better than a placebo. Trials testing it to induce labor have produced inconsistent results, and the evidence remains insufficient to say whether it helps with rheumatoid arthritis, PMS, or menopause symptoms. The honest takeaway: current research does not show that it works for the conditions people most often take it for.

There is no established or government-recommended dose. NCCIH does not publish standard dosing guidance for evening primrose oil, and the amount of oil in commercial products varies widely from brand to brand. Follow the directions on the product label, and importantly, speak with your doctor or pharmacist before starting it to discuss whether it is appropriate for you.

NCCIH indicates that evening primrose oil is probably safe for most adults taken by mouth. Less is known about its safety in children, and its safety during pregnancy or breastfeeding has not been clearly established, although the side effects reported when it was used to try to bring on labor were generally described as mild.

The side effects reported most often are gastrointestinal, such as abdominal (stomach) pain, nausea, and diarrhea.

NCCIH's current fact sheet does not list specific drug interactions, but it cautions that certain herbs and medications can interact in ways that are harmful. If you take any medication, check with your health care provider before using evening primrose oil or other herbal products.