Evening primrose oil is made from the evening primrose, a common name for a group of plants of the Oenothera genus. Such plants may also be called sun drops or sun cups, but more commonly, capsules of oil in herbal supplement sections of health food or natural foods stores are marketed as evening primrose. Most sold in the US is made from several species of the plant grown in Mexico and the United States.
Herbalists claim that evening primrose oil may be useful for people with heart disease. It may also help to regulate blood sugar, provide mood balance, and some use evening primrose as an oral or topical treatment for eczema. This oil has been suggested as a possible preventative treatment for breast cancer, an anti-inflammatory, a treatment for multiple sclerosis (MS), and potentially helpful in promoting weight loss. Most claims should be weighed against verifiable scientific evidence from clinical trials.
Scientific evidence has only established the possible benefits of evening primrose oil for the treatment of eczema and chronic dermatitis. Small studies on humans have shown that it might help control blood sugar, and may possibly be of help for people with psoriasis. Most other claims have not been proven by traditional double blind clinical trials. Early research suggests it does not promote weight loss, cardiac health, and is not effective in reducing inflammation in those who suffer from rheumatoid arthritis.
Most of the theoretical benefits of evening primrose oil are based on its components. It is high in omega-6 fatty acids, which contain linoleic acid, and gamma-linoleic acid (GLA). Omega-6 fatty acids are called polyunsaturated fats and are considered better than saturated fats. Yet, most studies conclude we consume too much omega-6, and consumption has been linked to heart disease, depression, asthma, cancer and obesity. While omega-6 fatty acids are essential, meaning our bodies don’t produce them, most Western diets include them in a much higher amount than is needed, which may mean evening primrose oil is not really a needed supplement. A good amount of research shows more potential benefit in taking supplements of omega-3 fatty acids as found in fish or flax seed oil, which humans generally consume in lower quantities.
Evening primrose oil is taken in relatively small doses, and few adverse effects have been reported from taking the supplement. It isn’t likely to have negative consequences on a person’s health, but it also may not be the best choice of herbal supplements for people. Mild side effects like stomach pain, diarrhea, and nausea are generally transient. If a person taking this oil experiences these beyond the third day of taking the supplement, they should stop taking it, and consult with a physician.
Some people should not take evening primrose oil. No studies exist as to its safety among pregnant or nursing women. Further, it is contraindicated for those who take medications to treat schizophrenia. People on medications like Thorazine®, Stelazine®, Mellaril®, or Prolixin® should never take this oil because it can result in life-threatening seizures. As with any herbal supplement or over the counter medicine, you should discuss its use with your physician prior to taking it.