Main constituents

  • Omega-6 type fatty acids: linoleic and gammalinoleic acid (LA, GLA) 

Major therapeutic interest

  • Relieving symptoms of PMS;
  • Reducing breast pain associated with PMS (mastalgia);
  • Treating osteoporosis: slows spinal column bone mass and bone mineral loss.

Other therapeutic interest / Traditional Use

  • Treating autoimmune disorders, particularly multiple sclerosis;
  • Treating eczema;
  • Relieving symptoms of chronic inflammation due to rheumatoid arthritis;
  • Slowing the progression of diabetic neuropathy;
  • Treating attention deficit disorder and hyperactivity in children;
  • Relieving menopause-related symptoms such as hot flashes and excessive sweating;
  • Treating chronic fatigue syndrome.


  • Epilepsy and seizure disorder: Lowers the epileptic threshold;
  • Schizophrenia: May cause convulsions;
  • Pregnancy: Safety for use during pregnancy has not yet been established.

Important Notice

  • One case is reported in the literature of a patient who had an epileptic seizure under anesthesia after consuming evening primrose oil. However, the concomitant use of other drugs was also noted.

Drug Interactions

Known human interactions

  • Increases the incidence of epileptic seizures when taken with anticonvulsants (Lamictal, Topamax, etc.);
  • Increases the incidence of epileptic seizures when taken with antipsychotics (Fluanxol, Largactil, etc.)

Suspected interactions

  • May heighten the effect of anticoagulant/antithrombotic drugs (Coumadin, Lovenox, heparin, etc.), antiplatelets (Plavix, Ticlid), as well as salicylic acid derivatives (acetylsalicylic acid or ASA, Aspirin, Entrophen, etc.) and other nonsteroidal anti-inflammatory drugs (NSAIDs) (Voltaren, Ibuprofen [Advil, Motrin], Naprosyn, etc.)

Scientific name

Oenothera biennis


Fever plant, King’s cure-all

Parts used

Seed oil