Randomised trial, 2005
Does evening primrose oil (gamma-linolenic acid) reduce PMS symptoms?
Yes. Women taking about 180 mg per day of gamma-linolenic acid showed greater improvements in PMS symptom duration, severity, and irritability compared to women taking placebo.
What they did
28 women diagnosed with PMS took either vegetable oil containing about 180 mg per day of gamma-linolenic acid (GLA) or placebo for three luteal phases. Researchers measured PMS symptoms daily and checked GLA levels in blood before and after treatment.
What they found
Before treatment, women with PMS had significantly lower levels of DGLA (a related compound) in their blood compared to women without PMS. After GLA treatment, women taking GLA had significantly higher levels of both GLA and DGLA in their blood compared to the placebo group and compared to their own baseline. Women taking GLA showed significantly greater improvement in the overall duration and severity of PMS symptoms and in irritability compared to those taking placebo.
What it means for you
GLA (from evening primrose oil) may help reduce how long PMS symptoms last and how severe they are, with possible effects on irritability. The study suggests GLA may work by restoring lower-than-normal blood levels in women with PMS. However, this was a small study (28 women) and needs confirmation in larger trials.
180 mg
Dose of GLA per day
28
Women studied
3
Treatment cycles
About the study
- Original title
- Efficacy of .GAMMA.-linolenic Acid for Treatment of Premenstrual Syndrome, as Assessed by a Prospective Daily Rating System
- Authors
- Shinji Watanabe, 櫻田 美穂, Hiroaki TSUJI et al.
- Journal
- Journal of Oleo Science
- Year
- 2005
- Study design
- Randomised trial
- What was tested
- Vegetable oil containing gamma-linolenic acid for three menstrual cycles
- Open access
- Yes
- Read the paper
- doi.org/10.5650/jos.54.217
Topics
Related studies
Systematic review, 2009
Which herbs, vitamins and minerals help treat PMS?
Systematic review, 2007
What treatments work for premenstrual syndrome?
Study, 2002
Which PMS treatments have good scientific evidence?
Randomised trial, 2000
Which dietary supplements help PMS?
Study, 2024
Does a combination of evening primrose oil, tocotrienol, and vitamin B6 reduce premenstrual symptoms?
Randomised trial, 2024
Does a herbal soft gel capsule with three oils reduce PMS symptoms?