Evening primrose oil and treatment of premenstrual syndrome

Med J Aust. 1990 Aug 20;153(4):189-92. doi: 10.5694/j.1326-5377.1990.tb136857.x.


The therapeutic effectiveness of evening primrose oil (Efamol, Vita-Glow) in the relief of 10 symptoms associated with premenstrual syndrome (PMS) as well as menstrual symptoms was studied in 38 women. The prospective trial was randomised, double-blind and placebo-controlled and was crossed-over after three cycles. Although the results showed an improvement in symptoms of PMS during the trial, no significant differences in the scoring between the active and placebo groups were found over six cycles. No "carry-over" effect of active medication was observed; the beneficial effect on all symptoms (psychological, fluid retention, breast) was rapid, the scores decreasing in the first cycle but increasing slightly at the change-over period after the third cycle, irrespective of whether the active or placebo medication was next given. These findings indicate that the improvement experienced by these women with moderate PMS was solely a placebo effect.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Double-Blind Method
  • Fatty Acids, Essential / therapeutic use*
  • Female
  • Follow-Up Studies
  • Humans
  • Linoleic Acids
  • Oenothera biennis
  • Placebo Effect
  • Plant Oils
  • Premenstrual Syndrome / drug therapy*
  • Premenstrual Syndrome / psychology
  • Randomized Controlled Trials as Topic
  • Statistics as Topic
  • gamma-Linolenic Acid


  • Fatty Acids, Essential
  • Linoleic Acids
  • Plant Oils
  • evening primrose oil
  • gamma-Linolenic Acid