What Evening Primrose Oil Is
Evening primrose oil is pressed from the seeds of Oenothera biennis and supplies gamma-linolenic acid, an omega-6 fatty acid. Remedy's Evening Primrose Oil provides 1300 mg per softgel, with 60 softgels per bottle.
It is a seed oil, not a plant hormone. That distinction settles most of the questions people arrive with.
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1300 mg per softgel: Single-ingredient seed oil.
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60 softgels: Two months at 1 daily.
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Active idea: Gamma-linolenic acid, an omega-6 fatty acid.
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Not: A phytoestrogen, unlike soy isoflavones or red clover.
The full claim map is in our evening primrose oil overview.
Supplement Facts
Serving size: 1 Softgel. Servings per container: 60.
| Amount Per Serving |
Amount |
% Daily Value |
| Evening Primrose Oil (Oenothera biennis seed oil) |
1300 mg |
† |
† Daily Value not established.
Directions: One softgel daily with food, or as directed by a healthcare practitioner.
Made in the USA.
What the Evidence Actually Shows
We would rather print the size of the evidence than describe it as proven, because the largest body of it is negative.
| Use |
Evidence |
Verdict |
| Eczema |
Cochrane: 27 studies, 1596 participants |
No significant improvement |
| Premenstrual syndrome |
2024 systematic review |
No demonstrated effectiveness |
| Cyclical breast pain |
85 enrolled, 41 completed, 6 months |
A trend, not beating placebo |
| Menopausal hot flashes |
2024 systematic review |
Some results |
| Skin hydration and barrier |
Healthy volunteers |
Positive |
| Starting labour, oral |
Triple-blind trial, 80 women |
No difference in anything |
Cochrane pooled 27 studies and found evening primrose oil failed to significantly improve global eczema symptoms on either the patient scale (MD 2.22, 95% CI -10.48 to 6.04) or the doctor scale (MD 3.26, 95% CI -6.96 to 0.45).[1]Oral evening primrose oil and borage oil for eczema — Cochrane Database of Systematic Reviews (2013) View source A 2024 review added 12 further conditions with no demonstrated effectiveness, premenstrual syndrome among them.[2]The effect of Oenothera biennis (Evening primrose) oil on inflammatory diseases: a systematic review of clinical trials — BMC Complementary Medicine and Therapies (2024) View source Both are set out in evening primrose oil for eczema and skin.
Hormones: What This Oil Is Not
The most common claim made for evening primrose oil is hormone balance, and the chemistry does not support it.
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What it supplies: Gamma-linolenic acid, a fatty acid.
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Structurally oestrogenic: No.
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Trials showing changed oestrogen: 0.
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Premenstrual syndrome: No demonstrated effectiveness.
We do not claim it balances hormones, raises oestrogen, or substitutes for hormone therapy. The detail is in for menopause and hormones.
Cyclical Breast Pain
This is the use with a dedicated trial, and the trial reported two numbers rather than one.
| Measure |
Result |
| Enrolled / completed |
85 / 41 |
| Dose |
3000 mg daily for 6 months |
| Worst-pain improvement within group |
p = 0.005 |
| Placebo within group |
p = 0.93 |
| Comparison against placebo |
p = 0.18, not significant |
Improving within a group is not the same as beating placebo, and the authors called it a pilot study showing a trend.[3]Vitamin E and evening primrose oil for management of cyclical mastalgia: a randomized pilot study — Alternative Medicine Review (2010) View source At 3000 mg a day that protocol needs between 2 and 3 of these softgels. The full reading is in evening primrose oil for breast pain.
Pregnancy: Read This Before Anything Else
Cervical ripening and starting labour are decisions made by a midwife or obstetrician. We do not give an amount, a route or a timing for it.
| Route |
Trial |
Result |
| Oral, the format sold here |
Triple-blind, 80 nulliparous women at 40 weeks |
No difference in any outcome |
| Oral dose used |
1000 mg twice daily for 7 days |
Gestational age, induction, Apgar all unchanged |
| Vaginal, a separate trial |
48 per group |
Bishop score 5.83 vs 5.19, p = 0.002 |
| Caesarean in that trial |
4 vs 2 |
Not significant, p = 0.677 |
The oral trial found no difference in gestational age at delivery, need for induction or augmentation, labour duration, neonatal weight or Apgar scores.[4]Evening primrose oil and labour, is it effective? A randomised clinical trial — Journal of Obstetrics and Gynaecology (2018) View source The vaginal result is a 0.64-point shift on a 13-point scale.[5]The Use of Evening Primrose Oil for Cervical Ripening in Low-Risk Women with Term Pregnancy: A Randomized Double-Blinded Controlled Trial — Complementary Medicine Research (2024) View source Both are in what the labour trials show.
How to Use It
One softgel daily with food is the starting point, and the trials used more for one specific reason.
| Question |
Practical answer |
| How much |
1 softgel of 1300 mg daily, with food |
| For cyclical breast pain |
The trial used 3000 mg, which is 2 to 3 softgels |
| Morning or night |
No trial compared the 2; pick one time |
| How long before judging |
Months, not weeks |
| Bottle life |
2 months at 1 daily, about 26 days at 3000 mg |
Amounts across every trial are compared in dosage and timing.
Safety and Who Should Avoid It
Mild digestive upset is the usual report. The two cautions that matter involve medication rather than the oil itself.
| Situation |
What to do |
| Warfarin, other anticoagulants or antiplatelets |
Ask before starting; bleeding-risk concern |
| Due for surgery |
Mention it and stop in advance |
| Seizure disorder, or taking phenothiazines |
Avoid unless cleared by a clinician |
| Pregnant or planning to use it near term |
A midwife or obstetrician decision |
| A new breast lump, skin change or nipple discharge |
Clinical assessment, not a supplement |
The full list is in side effects and who should avoid it.
Why Choose Remedy's Evening Primrose Oil
One ingredient, a stated amount, and an evidence summary that does not oversell it.
| What you get |
Why it matters |
| 1300 mg evening primrose oil per softgel |
A stated amount against trial doses of 1000 to 3000 mg |
| Single ingredient |
Any effect or reaction traces to 1 thing |
| 60 softgels |
Two months at 1 daily |
| No hormone claim |
It is a fatty acid oil, not a phytoestrogen |
| No labour claim |
The oral trial found no difference at all |
Frequently Asked Questions
What is the main use of evening primrose oil? +
Historically eczema, and that is where Cochrane pooled 27 studies in 1596 people and found no significant improvement.
Does evening primrose oil raise estrogen levels? +
There is no evidence that it does. It supplies 1 omega-6 fatty acid and is not structurally oestrogenic, unlike soy isoflavones.
Does evening primrose help balance hormones? +
Hormone balance is not a measurable outcome. Premenstrual syndrome was 1 of 12 conditions where a 2024 review found no demonstrated effectiveness.
Does it help breast pain? +
Within the treatment group, worst-pain improvement reached p = 0.005. The comparison against placebo was p = 0.18 and not significant.
Does evening primrose oil induce labor? +
The oral trial found no difference in gestational age at delivery across 80 women. Cervical ripening is a midwife or obstetrician decision.
Is it safe in pregnancy? +
The 2 pregnancy trials together covered 176 low-risk women, which is too small a base for a general safety statement. Ask your maternity team.
How much should I take? +
One softgel of 1300 mg daily with food. The breast-pain trial used 3000 mg, which is between 2 and 3 softgels.
When should I take it, morning or night? +
No trial compared the 2 directly. Taking it with a meal at 1 consistent time is the practical answer.
What are the bad side effects of evening primrose oil? +
Stomach upset, nausea and headache, usually dose-related. The 2 cautions that matter more involve anticoagulants and seizure risk.
Who should avoid evening primrose oil? +
Anyone on anticoagulants, anyone with a seizure disorder, anyone due for surgery, and anyone pregnant who has not asked. That is 4 groups.
Is it good for skin? +
Not for eczema, on 27 studies. In healthy volunteers, hydration and barrier function did improve, which is a narrower claim.
How long does 1 bottle last? +
Sixty softgels is 2 months at 1 daily, or about 26 days at the 3000 mg breast-pain protocol.
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