|Each softgel contains:|
|Certified organic evening primrose (Œnothera biennis) seed oil||500 mg|
|gamma-Linolenic acid (GLA) (10%)||50 mg|
|Linoleic acid (LA) (68%)||340 mg|
|Other ingredients: Natural vitamin E (from sunflower) in a softgel made of bovine gelatin, glycerin, and purified water.|
Evening primrose is native to North America. Originally used for the treatment of asthma, stomach and digestive disorders, and bruises, there is renewed interest in the herb because of the oil in this plant. Approximately 70% of the oil is cis-linoleic acid, and as much as 9% cis-gamma-linolenic acid (GLA). The oil also contains campestrol and beta-sitosterol. GLA is an essential polyunsaturated fatty acid that the body converts to a hormone-like substance called prostaglandin E1 (PGE1). PGE1 has anti-inflammatory properties and may also act as a blood thinner and blood-vessel dilator. The anti-inflammatory properties of EPO have been studied in double-blind research with people suffering from rheumatoid arthritis. Some, but not all, studies have reported that EPO supplementation provides significant benefits to these people. GLA, the primary active ingredient in EPO, has anticancer activity in test-tube experiments. Primrose oil has been used to treat the symptoms associated with premenstrual syndrome: irritability, headaches, breast tenderness, and bloating; it has also been helpful in the treatment of eczema. There are claims that increased doses help rheumatoid arthritis and slow the progression of multiple sclerosis.
Linoleic acid, a common fatty acid found in nuts, seeds, and most vegetable oils (including EPO), should theoretically convert to PGE1, but many things can interfere with this conversion, including disease, the aging process, saturated fats, hydrogenated oils, blood-sugar problems, and inadequate amounts of vitamin C, magnesium, zinc, and B vitamins. Supplements that provide GLA circumvent these conversion problems, leading to a more predictable formation of PGE1.
Despite the fact that most over-the-counter pain relievers and many prescription arthritis medicines work primarily by blocking prostaglandin synthesis, prostaglandins do play an important role in many biochemical reactions. Very few plants contain GLA in any significant quantity.
EPO is often used for premenstrual syndrome, allergies and bronchial asthma, high blood cholesterol, skin conditions (such as acne, eczema, and psoriasis), autoimmune conditions (multiple sclerosis, lupus, rheumatoid arthritis, and scleroderma), obesity, diabetes mellitus, and immune system depression.
Evening Primrose Oil is available in 500 mg or 1000 mg softgels. Most of the clinical trials have administered doses of 1–2 softgels two or three times daily, with a maximum adult dose of 4 g daily. In some conditions, up to three months may be needed to see a response.