Evening Primrose Oil

SCIENTIFIC NAME(S): Oenothera biennis L.
Family: Onagraceae

COMMON NAME(S): Evening primrose, EPO, OEP

Evening primrose oil (EPO) is obtained from the seeds of the evening primrose plant, a perennial found in North America. The leaves, roots and flowers of the evening primrose are all edible; the plan was used as a food source for many Native American tribes.

Evening primrose oil contains substantial amounts of poly saturated omega-6 fatty acids, essential fatty acids (EFAs) which are needed by the body to regulate a number of activities including insulin utilization, heart function, and mood. Since the body does not produce EFAs, they must be ingested through proper diet or supplementation.

Botany :- The evening primrose is a large, delicate wildflower native to North America and is not a true primrose. The blooms usually last 1 evening. Primrose is an annual or biennial and can grow in height from 1 to 3 m. The flowers are yellow and the fruit is a dry pod about 5 cm long, which contains many small seeds.The small seeds contain an oil characterized by its high content of gamma-linolenic acid (GLA).Wild varieties of O. biennis contain variable amounts of linoleic acid and GLA; however, extensive cross-breeding has produced a commercial variety that consistently yields an oil with 72% cislinoleic acid and 9% GLA. This is perhaps the richest plant source of GLA,although a commercially grown fungus has been reported to produce an oil containing 20% GLA and newer strains may produce even greater yields.

Uses of Evening Primrose Oil

EPO has been used to treat cardiovascular disease, breast disorders, premenstrual syndrome, mastalgia, rheumatoid arthritis, multiple sclerosis, atopic eczema, dermatological disorders and other illnesses.

Additional research indicates that individuals suffering from diabetes, scleroderma, Sjorgen's syndrome, and tardive dyskinesia may be deficient in GLA. In preliminary studies, supplementation with Evening Primrose Oil aided individuals with these conditions.

Side Effects of Evening Primrose Oil

Indigestion, nausea, soft stools, or headache may occur. If any of these effects persist or worsen, contact your doctor promptly. If you notice other effects not listed above, contact your doctor or pharmacist.


Although many people may have inadequate levels of GLA, the optimal intake for this nutrient remains unknown. Researchers often use 3,000-6,000 mg of EPO per day, which provides approximately 270-540 mg of GLA.


As a nutritional supplement,the maximum label-recommended daily dose of EPO is approximately 4 g.This dose contains 300 to 360 mg GLA, which contributes: (1) 6 to 7 mg GLA/ kg/day likely to be produced from linoleic acid in the healthy adult female, (2) 23 to 65 mg GLA/kg/day consumed by a breastfed baby or (3) 70 to 400 mg/ kg/day of all the metabolites of linoleic acid consumed by a breastfed infant. According to these estimates, the amounts of GLA in the recommended doses of EPO are in the same range as the amounts of GLA and other related EFAs present in widely consumed foods. Thus, there is little concern about the safety of EPO as a dietary supplement in the recommended dosage range. In toxicological studies carried out for 1 year, EPO at doses up to 2.5 mL/kg/day in rats and 5 mL/kg/day in dogs was found to possess no toxic properties. Similar results were obtained in 2-year carcinogenicity and teratological investigations. With about 1000 tons of EPO sold in several countries as a nutritional supplement since the 1970s, there have been no complaints concerning the safety of the product.

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