If you're approaching menopause or have already entered menopause, you might be concerned about some of the symptoms, such as hot flashes and difficulty sleeping. Although symptoms can vary greatly among women, they may interfere with quality of life and cause other problems. Oil prepared from the evening primrose plant (Oenothera biennis) is a traditional remedy for some of these symptoms that may have benefits during menopause.
The evening primrose is named for its unusual habit of opening new flowers after sunset or on a cloudy, sunless day. When crushed, the plant's seeds produce an oil with several compounds that have biological activity. Twenty-five percent of the oil is made of fatty acids and one of these, gamma-linoleic acid or GLA, is an omega-6 fatty acid called essential because you need to obtain it from food. GLA and other compounds in evening primrose oil may also help lessen symptoms of menopause.
Evening primrose oil has been part of herbal medicine for hundreds of years, recommended by practitioners for many reasons, including relief from hot flashes that arise just before and during menopause. Research into the usefulness of the oil for this purpose has had mixed results. A study published in the December 2009 issue of "American Family Physician" reviewed a number of trials involving its use and reported inconclusive results, stating that most studies provided only preliminary findings and were generally inconclusive. A later study published in the November 2013 issue of "Archives of Gynecology and Obstetrics" included 56 menopausal subjects who took either evening primrose oil or a placebo for six weeks. Women who consumed the oil reported hot flashes of lessened severity, compared to the placebo group, leading the authors to conclude that the oil had some positive benefit.
Evening primrose oil is available from health food stores in capsules. The oil is perishable and capsules should be stored out of sunlight and under refrigeration to prevent spoilage. Opt for high-quality oil certified as organic and is standardized to at least 8 percent GLA to minimize differences between batches. No minimal effective dose of the oil has been established, but clinical studies have used doses between 2 to 8 grams daily, sometimes divided into several doses, without negative effects.
Side Effects and Precautions
Evening primrose oil is generally considered a safe supplement, but may cause mild nausea, stomach pain or headache in some people. Pregnant or breast-feeding women should avoid it, and it shouldn't be taken by anyone with epilepsy or another seizure disorder. It may raise the risk of bleeding and shouldn't be combined with blood-thinning medications. Primrose oil could also interact with drugs prescribed for high blood pressure, depression or seizures. If you're approaching or in menopause and have questions about evening primrose oil, talk to your doctor to decide if the oil might be helpful for you.
- University of Maryland Medical Center: Evening Primrose Oil
- Memorial Sloan-Kettering Cancer Center: Evening Primrose Oil
- Archives of Gynecology and Obstetrics: The Effect of Oral Evening Primrose Oil on Menopausal Hot Flashes -- A Randomized Clinical Trial
- Drugs.com: Evening Primrose Oil
- American Family Physician: Evening Primrose Oil