Evening primrose is a plant native to North and South America. It also grows throughout Europe and parts of Asia. It has yellow flowers which open at sunset and close during the day. The oil from the seeds of evening primrose is used to make medicine.
Evening primrose is taken by mouth for skin disorders such as eczema (atopic dermatitis), psoriasis, acne, and dry, itchy, or thickened skin (ichthyosis). It is also used for rheumatoid arthritis, a type of arthritis that affects people with psoriasis, weak bones (osteoporosis), bone loss (osteopenia), Raynaud's syndrome, multiple sclerosis (MS), Sjogren's syndrome, dry eyes, liver cancer, hepatitis B, severe itchy skin due to biliary cirrhosis, high cholesterol, heart disease, a movement disorder in children called dyspraxia, a learning disorder characterized by reading problems (dyslexia), leg pain due to blocked blood vessels (intermittent claudication), alcoholism, a nerve condition usually caused by certain psychiatric drugs (tardive dyskinesia), Alzheimer's disease, and schizophrenia.
Some people take evening primrose by mouth for chronic fatigue syndrome (CFS), asthma, nerve damage related to diabetes, attention deficit-hyperactivity disorder (ADHD), and obesity. Evening primrose is also taken by mouth for stomach and intestinal disorders including ulcerative colitis, irritable bowel syndrome, and peptic ulcer disease.
Women take evening primrose by mouth during pregnancy for preventing high blood pressure (pre-eclampsia), shortening labor, starting labor, and preventing late deliveries. Women also use evening primrose for premenstrual syndrome (PMS), breast pain, and symptoms of menopause such as hot flashes. It is also taken by mouth for endometriosis, a condition in which tissue that normally lines the uterus grows outside the uterus.
Evening primrose is applied to the skin for eczema (atopic dermatitis).
In foods, the oil from evening primrose is used as a source of essential fatty acids.
In manufacturing, the oil from evening primrose is used in soaps and cosmetics.
In Britain, evening primrose used to be approved for treating eczema and breast pain. However, the Medicines Control Agency (MCA), which is the British equivalent of the US Food and Drug Administration (FDA), withdrew the licenses for evening primrose products marketed as prescription drug products for these uses. The licenses were withdrawn because the agency concluded that there is not enough evidence that they are effective. The manufacturer disagreed, but it hasn't published studies yet to prove the effectiveness of evening primrose for these uses.
How it works
Evening primrose oil contains gamma-linolenic acid which is an omega-6 essential fatty acid. It is involved in regulating inflammation and the immune system.
Several small studies show that taking 15-20 mL or 4-6 grams of evening primrose daily for up to 16 weeks does not improve asthma symptoms.
Taking evening primrose, up to 4 grams daily for 4-6 weeks, does not seem to improve ADHD symptoms in children. Taking a specific supplement containing fish oil and evening primrose (Eye Q, Equazen / Novasel) daily for 12 weeks does seem to improve some symptoms in children 7-12 years-old. But it's not clear if this benefit is due to evening primrose or fish oil.
Early research shows that taking evening primrose during pregnancy does not reduce blood pressure in women with pregnancy-induced high blood pressure or a condition called pre-eclampsia. Taking a combination of evening primrose and fish oil during pregnancy may reduce the risk of tissue swelling (edema). However, the combination also does not reduce the risk of high blood pressure.
Evening primrose is LIKELY SAFE for most people when used in doses up to 6 grams daily for up to a year. When taken by mouth, it can sometimes cause mild side effects including upset stomach, nausea, diarrhea, and headache.
Pregnancy and breast-feeding: Taking evening primrose by mouth isPOSSIBLY SAFEduring pregnancy. Taking up to 4 grams daily for up to 10 weeks during pregnancy seems to be safe. But until this is confirmed by additional research, it is best to stay on the safe side and avoid use, Taking evening primrose during the last weeks of pregnancy might delay labor. Don't use close to the end of pregnancy.Are there any interactions with medications?
It is POSSIBLY SAFE to take evening primrose oil during breast-feeding, but it's best to check with your healthcare provider first.
Bleeding disorders: There is a concern that evening primrose might increase the chance of bruising and bleeding. Don't use it if you have a bleeding disorder.
Epilepsy or another seizure disorder: There is a concern that taking evening primrose might make seizures more likely in some people.
Schizophrenia: Seizures have been reported in people with schizophrenia treated with phenothiazine drugs, GLA (a chemical found in evening primrose oil), and vitamin E. Get your healthcare provider's opinion before starting evening primrose.
Surgery: Evening primrose might increase the chance of bleeding during or after surgery. Stop using it at least 2 weeks before a scheduled surgery.
Lopinavir / ritonavir (Kaletra) is changed and broken down by the body. Evening primrose might decrease how quickly the body breaks down lopinavir / ritonavir (Kaletra). Taking evening primrose along with lopinavir / ritonavir (Kaletra) might increase the levels and effects of lopinavir / ritonavir (Kaletra).Medications used during surgery (Anesthesia)
Evening primrose contains GLA (gamma-linolenic acid), which might slow blood clotting. Taking evening primrose along with medications that also slow clotting might increase the chances of bruising and bleeding.Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), and naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.Evening primrose might interact with medications used during surgery. One person who was taking evening primrose and other medications had a seizure during surgery. But there isn't enough information to know if evening primrose or the other medications caused the seizure. Be sure to tell your doctor what natural products you are taking before having surgery. To be on the safe side, you should stop taking evening primrose at least 2 weeks before surgery.
MinorMedications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)
Taking evening primrose with phenothiazines might increase the risk of having a seizure in some people.Some phenothiazines include chlorpromazine (Thorazine), fluphenazine (Prolixin), trifluoperazine (Stelazine), thioridazine (Mellaril), and others.Some medications are changed and broken down by the liver. Evening primrose might decrease how quickly the liver breaks down some medications. Taking evening primrose along with some medications that are changed by the liver might increase the effects and side effects of these medications. Before taking evening primrose, talk to your healthcare provider if you take any medications that are changed by the liver.Some of these medications that are changed by the liver include celecoxib (Celebrex), diclofenac (Voltaren), fluvastatin (Lescol), glipizide (Glucotrol), ibuprofen (Advil, Motrin), irbesartan (Avapro), losartan (Cozaar), phenytoin (Dilantin), piroxicam (Feldene), tamoxifen (Nolvadex), tolbutamide (Tolinase), torsemide (Demadex), and warfarin (Coumadin).Some medications are changed and broken down by the liver. Evening primrose might decrease how quickly the liver breaks down some medications. Taking evening primrose along with some medications that are changed by the liver might increase the effects and side effects of these medications. Before taking evening primrose, talk to your healthcare provider if you take any medications that are changed by the liver.Some medications changed by the liver include lovastatin (Mevacor), clarithromycin (Biaxin), cyclosporine (Neoral, Sandimmune), diltiazem (Cardizem), estrogens, indinavir (Crixivan), triazolam (Halcion), and others.