There are no health warnings for evening primrose oil to prevent men from using it. While some of the uses are specific to women, WebMD says it has potential benefits for other conditions, including eczema and rheumatoid arthritis, that affect men.
While most people experience few problems with the oil, potential side effects include headache, nausea and stomach upset, according to WebMD. It also can cause problems when used with prescription medications. Primrose oil increases the risk of bleeding when used with anticoagulant medication. With certain drugs for psychotic disorders, it causes serious nausea, vomiting and increases the risk of seizures. The supplement potentially lowers blood pressure and interacts with depression medication. Because of a potential problem with anesthesia, surgery patients should discuss use of this supplement with their doctor before their procedure, WebMD cautions.
Mature seeds of the evening primrose contain seven to 10 percent gamma-linolenic acid. The oil from these seeds is the ingredient in the evening primrose oil supplement, according to Reference.com.
Health food stores and pharmacies that offer herbal supplements usually carry evening primrose oil in capsules. Women often use the oil to reduce symptoms of PMS and menopause, says About.com. Some evidence indicates that the supplement improves the body's response to the breast cancer drug tamoxifen.