Evening Primrose Oil (Oenothera biennis)
Evening primrose oil is a rich source of the long-chain fatty acid gamma linolenic acid
(GLA). It contains 9% GLA, as well as 74% linoleic acid, 11% oleic acid, 6% palmitic acid,
and 2% stearic acid.
Alternate names
 Fever plant
 OEP (oil of evening primrose)
 Sun drop
Native to
 North temperate zone of North America, especially at high altitudes
Medicinal parts used
 Pressed oil, extracted from the seeds
Uses
 Allergy-induced eczema
 Premenstrual syndrome (PMS)
 Mastalgia (breast pain and tenderness)
 Rheumatoid arthritis
 Hypertension and elevated serum lipids
How it works
 Linoleic acid may play a role in the way that the body utilizes insulin, maintains weight,
and resists cancer and heart disease
 GLA is believed to interrupt the body's production of chemicals that initiate and maintain
inflammation
Side effects and warnings
 Generally regarded as safe
 Individuals at risk for seizures, who have epilepsy, or are pregnant should not take evening
primrose oil
 Large doses may cause loose stools
 Individuals taking Coumadin/warfarin, aspirin, or nonsteroidal anti-inflammatory drugs
(NSAIDs) should not take evening primrose oil
 Individuals taking other herbals that affect blood clotting, such as devil’s claw, garlic,
ginger, horse chestnut, red clover, saw palmetto, should not take primrose evening oil
Dosage recommendations
 Usual recommended dosage for atopic dermatitis or eczema: 4−8 grams (g)/day, divided in
two doses
 Usual recommended dosage for breast pain: 3-4 g/day, divided in two doses
References and recommended readings
Drugs.com. Oil of evening primrose (EPO) (OEP). Available at:
http://www.drugs.com/npc/oil-of-evening-primrose-epo-oep.html. Accessed March 29, 2011.
MedlinePlus.gov. Evening primrose oil. Available at:
http://www.nlm.nih.gov/medlineplus/druginfo/natural/1006.html. Accessed March 29, 2011.
National Center for Complementary and Alternative Medicine. Evening primrose oil.
Available at: http://nccam.nih.gov/health/eveningprimrose/. Accessed March 29, 2011.
Review Date 5/11
G-1641