Ingredient evidence
Evening primrose oil
A supplement sold for almost every women's health symptom, with usable evidence for exactly one of them.
Also sold as: EPO, gamma-linolenic acid, GLA.
Our read of the evidence
Limited evidence
Little or no good human data. Mostly marketing.
Reasonable to try for cyclical breast tenderness. Unlikely to do anything for hot flushes.
What the evidence actually shows
Evening primrose oil became popular on the theory that GLA corrects an imbalance in prostaglandin production. Trials have not been kind to it. For eczema, systematic reviews found no benefit over placebo, and it lost its UK licence for that use. For PMS overall, the data is weak.
Cyclical breast pain is the exception where clinical practice still sometimes includes it. Trial results are mixed, but the side effect profile is mild and some breast clinics have historically suggested a three-month trial. If it has not helped in three months, it will not.
For hot flushes, the small number of trials give inconsistent results and any effect is minor. It is a poor first choice for menopausal symptoms.
How to take it.
- Typical dose
- 1,000-3,000mg daily
- Form
- Capsules, standardised for GLA content
- Timing
- Daily with food
- Worth knowing
- Give it three months for cyclical breast pain, then stop if there is no change. Check the GLA content, not just the oil weight.
What it will not do.
- It will not treat eczema - trials found no benefit
- It will not reliably improve PMS mood symptoms
- It will not meaningfully reduce hot flushes
Who should avoid it.
- You have epilepsy or a seizure disorder - there are case reports of lowered seizure threshold
- You are pregnant, unless advised otherwise
- You are due surgery within two weeks
Raise with a prescriber
- May increase bleeding risk with anticoagulant or antiplatelet medicines
- Caution with phenothiazine antipsychotics due to seizure risk reports
Products containing evening primrose oil.
Everything below is stocked in the UK. Compare on the active dose and the cost per day rather than the size of the pack.
| Product | Key actives | Form | Price | Per day | Best for |
|---|---|---|---|---|---|
| Wellwoman OriginalVitabiotics | Iron, B vitamins, Evening primrose oil | Capsule | ~£12 | - | Busy weeks and irregular eating, A general nutritional floor |
| Wellwoman MaxVitabiotics | Omega-3 EPA/DHA, Iron, B vitamins | Tablets + capsules | ~£20 | - | Women who do not eat oily fish, Anyone consolidating several supplements |
| Viridian Organic Evening Primrose OilViridian Nutrition | GLA from evening primrose oil | Liquid | £23.05 | 58p | Cyclical breast tenderness, as a trial |
| Igennus Vegepa EPA with Evening Primrose OilIgennus Healthcare Nutrition | EPA, GLA from evening primrose oil | Softgel | £15.95 | 53p | Period pain, Low oily fish intake, Cyclical breast tenderness, as a trial |
Prices are the brand's UK list price at the time of writing and change often. Cost per day is calculated from pack size and the label's daily serving, and is shown only where both are published.
Common questions.
Does evening primrose oil help menopause symptoms?
The evidence for hot flushes is weak and inconsistent. It is not a good first choice for menopausal symptoms.
Does evening primrose oil help breast pain?
This is its most defensible use. Trials are mixed but the safety profile is mild, so a three-month trial is reasonable if cyclical breast tenderness is your main symptom.
How long should I take evening primrose oil?
Three months is a fair trial. If nothing has improved by then, stop.
Where this comes from.
A supplement is not clinical care.
If symptoms are affecting your work, your sleep or your relationships, the useful next step is an assessment rather than another purchase. Our check-in takes three minutes and points you to the right kind of clinician.
Related on Clarity Clinic
Other ingredients
Good evidence. Worth taking if you rarely eat oily fish, and genuinely important in pregnancy. Not a mood treatment on its own.
Mixed evidence. A reasonable, cheap thing to try for PMS at 50-100mg. Never go above the labelled limit.
Reasonable evidence. Genuinely useful if you are low in magnesium or sleeping badly. Not a sedative, and not a cure for anxiety.
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Food supplements are not medicines and are not intended to diagnose, treat or cure any condition. They should not replace a varied diet or prescribed treatment. If you are pregnant, breastfeeding, taking medication or managing a diagnosed condition, check with a pharmacist or clinician before starting anything on this page. We do not accept payment for inclusion or placement. Where a link earns us a commission we say so on the product page. Last reviewed 27 August 2026.