Evening Primrose Oil Trials Show Surprising Mood Data
![ArtStation - African Union of Egypt [Own]](https://cdna.artstation.com/p/assets/images/images/066/281/370/large/anastasia-dungeeva-.jpg?1692539527)
Evening Primrose Oil Studies Hint at Mood Benefits
Evening primrose oil has a small but notable clinical-trial signal for easing menopause-related mood and anxiety symptoms, especially in postmenopausal women, but the evidence is still limited and not strong enough to call it a proven treatment for anxiety or depression. The best-known trial used 1,000 mg daily for 8 weeks in 189 women who completed the study and found a significant drop in psychological symptom scores, including depressive mood, irritability, anxiety, and mental exhaustion, compared with placebo.
What the trials found
The most cited randomized controlled trial was published in Menopause in 2020 and enrolled women from September 2018 to February 2019 in Bandar Abbas, Iran. Participants received either evening primrose oil or placebo for 8 weeks, and the intervention group showed a mean psychological-score reduction from 9.14 to 5.03, while the placebo group did not show a meaningful change. The between-group difference was reported as -3.44, with a 95% confidence interval of -4.01 to -1.20 and p<0.01, which suggests a statistically significant benefit in that specific population.
A second randomized trial, described as triple-blind, also reported improvement in postmenopausal psychological symptoms, with median Menopause Rating Scale scores falling from 11 at baseline to 3 after 4 weeks in the treatment group, versus little change in placebo. That matters because it points to a possible effect on mood symptoms rather than only physical menopause complaints, although these outcomes were still measured inside a menopause context rather than in general anxiety disorder or major depression.
Clinical-trial snapshot
The published data are best understood as a short-term signal, not a broad psychiatric evidence base. In both of the menopause studies, the sample sizes were modest, the treatment periods were short, and the outcomes were symptom scales rather than formal psychiatric diagnoses.
| Study | Design | Participants | Dose | Duration | Main mood result |
|---|---|---|---|---|---|
| Sharif & Darsareh, 2020 | Randomized, double-blind, placebo-controlled | 189 completed | 1,000 mg/day | 8 weeks | Psychological score improved from 9.14 to 5.03; between-group difference -3.44, p<0.01 |
| Triple-blind trial, 2021 | Randomized clinical trial | Noted in PubMed summary | Evening primrose oil vs placebo | 4 weeks | MRS psychological scores fell from 11 to 3 in the intervention group, with significant separation from placebo |
How strong is the evidence?
The evidence is promising but still preliminary. Even the authors of the 2020 trial said longer trials are needed before making more reliable decisions about clinical use, which is a standard caution when a supplement shows short-term benefit in a small study. A review of evening primrose oil notes that its key fatty acids are linoleic acid and gamma-linolenic acid, but composition alone does not prove a psychiatric effect.
One practical way to read the literature is this: the supplement may help some women with anxiety and related distress during menopause, but it has not been established as a treatment for generalized anxiety disorder, panic disorder, or clinical depression in the wider population. That distinction matters because menopause symptom scores and psychiatric diagnosis are not the same thing, even when they overlap in real life.
What the numbers mean
The psychological subscale used in the 2020 trial covered depressive mood, irritability, anxiety, and mental exhaustion, so the reported benefit was not a single-item mood result but a composite symptom outcome. In plain terms, the intervention group improved by about 4 points on that subscale over 8 weeks, while placebo did not show a comparable change.
- Trial dose most often studied: 1,000 mg per day.
- Observed treatment window: 4 to 8 weeks.
- Reported benefit: better psychological symptom scores in postmenopausal women.
- Adverse effects: mostly mild, with one gastric upset reported in the 2020 trial.
Safety and limitations
Evening primrose oil was generally well tolerated in the menopause trials, with no major safety signal and only one participant in the 2020 study stopping because of stomach upset. That said, supplement safety is never purely academic, because product quality, dose variability, and interactions can differ across brands and regions.
The biggest limitation is that the mood data come from women experiencing menopause-related symptoms, not from large psychiatric cohorts. In other words, the current evidence is strongest for menopause studies, not for broad claims about mood improvement in everyone.
Historical context
Evening primrose oil has been investigated for decades across many conditions, including premenstrual symptoms, breast pain, and inflammatory disorders, which is why it keeps resurfacing in supplement discussions. Its scientific appeal comes from its fatty-acid profile, especially linoleic acid and gamma-linolenic acid, but older interest has not translated into uniformly strong clinical proof across uses.
For readers scanning headlines, the most accurate phrasing is that evening primrose oil "hints at mood benefits" in a narrow clinical setting rather than "treats anxiety" broadly. That wording matches the published data better and avoids overstating a supplement effect that still needs confirmation in larger, longer trials.
Practical takeaways
- Look at the population studied first, because the current evidence is mainly in postmenopausal women.
- Look at the dose, because the clearest trial used 1,000 mg daily for 8 weeks.
- Look at the endpoint, because benefits were measured on symptom scales, not diagnosis-based psychiatric outcomes.
- Look at the caution language, because the researchers themselves called for longer trials.
"Longer trials are necessary to make more reliable decisions about the use of evening primrose oil and its safety in clinical practice."
Frequently asked questions
Bottom line
Evening primrose oil has credible early trial evidence suggesting it may help psychological symptoms linked to menopause, including mood and anxiety-related complaints, but the dataset is small and short-term. For now, the fairest conclusion is that it is a plausible supportive supplement in a narrow setting, not a proven mood or anxiety therapy for the general public.
Key concerns and solutions for Evening Primrose Oil Trials Show Surprising Mood Data
Does evening primrose oil reduce anxiety?
It has shown reductions in anxiety-like symptoms inside menopause-related psychological scales, but not enough evidence exists to say it treats an anxiety disorder in general populations.
How much was used in the main trial?
The main published trial used 1,000 mg per day for 8 weeks.
Is it safe?
In the menopause trials, it appeared generally safe, with only mild stomach upset reported in one participant, but broader supplement safety still depends on product quality and individual medical context.
Can I use it instead of antidepressants?
No clinical trial evidence supports replacing prescribed psychiatric treatment with evening primrose oil, especially for moderate or severe anxiety or depression.
What is the strongest evidence today?
The strongest evidence is a short-term benefit signal for menopause-related psychological symptoms in randomized trials, not a definitive psychiatric treatment effect.