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Evening primrose oil: what the research says

38 studies on evening primrose oil in PMS and PMDD, each explained in plain English. 4 of them use the strongest designs: randomised trials and systematic reviews.

Randomised trial 13Review 9Study 7Systematic review 5Survey study 3Non-randomised trial 1
Systematic review, 2009

Which herbs, vitamins and minerals help treat PMS?

Only calcium has good evidence to work for PMS. Chasteberry and vitamin B6 may help, but most of the 62 products people try lack proper research.

Systematic review, 2007

What treatments work for premenstrual syndrome?

Many treatments have been studied for PMS, but researchers face a major challenge: there is no standard way to measure symptom severity, making it difficult to know which treatments truly work.

Study, 2002

Which PMS treatments have good scientific evidence?

Calcium at 1200 mg daily and certain antidepressants have good evidence of working. Many popular treatments like vitamin B6, evening primrose oil, and birth control pills lack strong evidence. Some treatments like progesterone do not work.

Randomised trial, 2000

Which dietary supplements help PMS?

Only calcium has strong evidence from large rigorous trials. Magnesium, vitamin E, and carbohydrate supplements show limited promise but need more research. Vitamin B6 and evening primrose oil have mixed results.

Study, 2024

Does a combination of evening primrose oil, tocotrienol, and vitamin B6 reduce premenstrual symptoms?

Yes. In women with PMS taking this combination for 3 months, premenstrual symptoms improved significantly. The overall PMS score dropped by 61.03%, menstrual pain dropped by 75.20%, and breast tenderness dropped by 82.54%.

Randomised trial, 2024

Does a herbal soft gel capsule with three oils reduce PMS symptoms?

The capsule reduced women's PMS symptoms when compared to their baseline, but was not significantly better than taking sunflower oil.

Review, 2023

Can herbs and supplements help with PMS symptoms?

Herbs like chaste berry and supplements like calcium and magnesium may help with PMS. Evidence is strongest when combined with lifestyle changes and therapy, though more research is needed.

Review, 2021

Do herbal products help with PMS?

Chaste tree shows effectiveness for PMS, but more research is needed. Evidence for other herbs is still developing.

Randomised trial, 2019

Do evening primrose oil or vitamin B6 ease PMS symptoms better than placebo?

Evening primrose oil significantly reduced PMS symptom severity, while vitamin B6 did not beat placebo in this trial.

Randomised trial, 2018

Does evening primrose help premenstrual syndrome?

Yes. Evening primrose 1000 mg twice daily for 2 months significantly reduced PMS severity compared to placebo, with few side effects.

Systematic review, 2011

Do herbal treatments help PMS and PMDD?

Vitex agnus castus seems to reduce symptoms better than placebo. Ginkgo biloba and crocus sativus might help, but evening primrose oil and St. John's Wort do not.

Randomised trial, 2010

Can femicomfort (vitamin B6, E, and evening primrose oil) relieve PMS symptoms?

Yes. Women taking femicomfort reported relief of PMS symptoms compared to placebo. The supplement was well-tolerated with no significant increase in side effects.

Study, 2009

Does evening primrose oil help treat PMS?

No. Based on current evidence, evening primrose oil is likely ineffective for PMS. Most studies to date have had major methodologic flaws.

Randomised trial, 2006

Which dietary supplements and herbs work for PMS?

Calcium and vitamin B6 have the best evidence for PMS. Evening primrose oil and magnesium have conflicting results. Other supplements like Vitex need more and better research.

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.

Review, 2003

Do complementary and alternative medicine treatments work for PMS and PMDD?

Some treatments like exercise, mind-body approaches, and certain herbs and supplements have good evidence of working. Many other approaches lack conclusive evidence.

Review, 2003

What treatments work best for PMS and PMDD?

There is no single best treatment. For mild PMS, lifestyle changes help. For moderate symptoms, selective serotonin reuptake inhibitors (SSRIs) like fluoxetine and sertraline are most effective. Calcium and evening primrose oil may offer modest benefit.

Study, 1998

Does diet and supplements help PMS?

Yes, some dietary changes and supplements may help PMS. Magnesium and vitamin B6 are helpful for some women. Results usually appear after 3-4 months.

Randomised trial, 1993

Do essential fatty acids help premenstrual syndrome?

No. Essential fatty acids did not reduce PMS symptoms compared to placebo. Some improvement was seen over time but was likely due to placebo effect or the act of being in a study.

Randomised trial, 1993

Do women with PMS have different hormone and chemical levels, and do essential fatty acids change them?

Hormone and chemical levels were mostly the same in PMS and healthy women, except aldosterone was lower and cholesterol higher in PMS. Essential fatty acids did not change any of these levels.

Randomised trial, 1990

Does evening primrose oil help PMS symptoms?

No. There were no significant differences between evening primrose oil and placebo. The symptom improvements women experienced were solely due to placebo effect.

Randomised trial, 1983

Does evening primrose oil help premenstrual syndrome?

Yes. Studies found evening primrose oil highly effective for depression, irritability, breast pain, and fluid retention. The strongest evidence comes from 3 double-blind controlled trials.

Study, 2026

Does evening primrose oil help teenage girls and young women with menstrual cycle problems?

86.79% had improvements. Girls with PMS reported better sleep and memory. Those with PCOS reported better mood and appearance.

Review, 2025

What are the most effective ways to manage mild premenstrual syndrome?

Lifestyle changes including exercise, healthy eating, reducing caffeine and salt, and stress management can help. Some supplements like evening primrose oil and calcium may offer modest benefits.

Survey study, 2024

What do pharmacy students know about using herbs for PMS?

Pharmacy students had moderate knowledge (58.9% correct answers) about these herbs, and about 83% believed the herbs could help PMS symptoms. However, this study only surveyed opinions. It did not test whether these herbs actually work.

Review, 2024

Can herbal remedies and lifestyle changes help manage premenstrual syndrome?

A review suggests that herbs like Chaste Tree, Evening Primrose Oil, Dong Quai, and Ginger, combined with diet and exercise, may help relieve PMS, though individual responses vary and clinical evidence is limited.

Review, 2022

Does evening primrose oil help PMS symptoms?

The research is mixed. Some studies showed evening primrose oil reduced symptom severity and duration, but others found no difference from placebo. We need more research to know for sure.

Systematic review, 2022

Can diet and herbal medicine help with PMS symptoms?

Few studies exist, but the review suggests eating well is important for managing PMS. Three herbal medicines show potential: Vitex Agnus Castus, Angelica sinensis, and evening primrose oil, though stronger evidence is needed.

Review, 2021

Can diet help with PMS and other menstrual disorders?

Diet may help. Eating fresh whole foods while avoiding refined carbohydrates, salt, and alcohol is recommended. Evening primrose oil appears to have positive effects on PMS.

Study, 2016

What are the features of premenstrual syndrome and how is it treated?

Premenstrual syndrome is a common disorder of young and middle-aged women with emotional and physical symptoms during the luteal phase. Calcium and evening primrose oil supplements may offer modest benefit.

Review, 2002

What supplements or alternative treatments help PMS symptoms?

Several supplements show evidence for helping PMS: calcium, magnesium, vitamin E, thiamine (vitamin B1), and omega-3 fatty acids. Japanese herbal formulas may also help.

Survey study, 1997

How common are premenstrual symptoms, what treatments do women use, and do they work?

Between 11-32% reported severe or extreme symptoms, and 85% had tried treatments. Women reported that dietary changes, evening primrose oil, vitamins, and exercise worked best.

Systematic review, 1996

Does evening primrose oil help premenstrual syndrome?

Probably not. The best-designed studies found no benefit, though the studies were small enough that a small effect can't be completely ruled out.

Study, 1992

Does a supplement with linolenic acid, calcium, and iron help premenstrual syndrome symptoms?

A small trial found improvements in energy, PMS symptoms, and skin condition after two months. However, the abstract provides no specific numbers, so we cannot know how large the improvements were.

Randomised trial, 1988

Do hormones respond differently in women with PMDD?

Two hormones (AVP and OT) increased similarly after an injection in women with and without PMDD, with no difference between groups or across menstrual cycle phases. This is a very small preliminary study.

Survey study, 1988

Could changes in blood thickness and red blood cell shape cause premenstrual syndrome?

This paper proposes that PMS may be caused by abnormal changes in blood thickness and red blood cell deformability during the menstrual cycle. This is a theoretical hypothesis, not proven research.

Non-randomised trial, 1985

Does Efamol help severe PMS?

Yes. Efamol reduced PMS symptoms and depression better than placebo. It may work by changing how blood platelets function.

Randomised trial, 1983

Which nutritional supplements help treat premenstrual syndrome?

Vitamin B6 at 40-100 mg twice daily is widely used for PMS, especially in milder cases. Evening primrose oil at 2-3 g per day shows encouraging early results. Other nutritional approaches may help but are unlikely to provide complete relief alone.