Evening primrose oil,
does it really help with Relief of cyclical mastalgia?
research showsEvening primrose oil is rated D because two independent randomized trials did not show benefit over placebo or control oil for cyclical mastalgia. Pruthi 2010 randomized 85 women, but only 41 were actually assessed at six months. The primary modified McGill Breast Pain Questionnaire comparison between evening primrose oil and placebo failed with P=0.18; the within-group P=0.005 does not establish a placebo-controlled effect. Blommers 2002 randomized 120 women and found pain-day reductions of 12.3% versus 13.8% in an intention-to-treat comparison, P=0.73. High attrition and conflicting recent small reports support D rather than F, with 24 points.
ads claimA fatty-acid mechanism and within-group improvement can be presented as proven placebo-controlled relief. Between-group results that separate natural fluctuation and placebo response were negative.
Useful facts when choosing a product
- The Pruthi trial used evening primrose oil 3,000 mg daily for six months.
- A pain diary can establish cyclicity; a new lump, bloody discharge, or skin retraction requires clinical assessment.
- Gamma-linolenic acid content and supplement quality may differ between products.
Chamgap Semantic Classification Code
Candidate index · review held
S.evening-primrose-oil.UNK.cyclical-mastalgia.relieve.MULTISupplements and nutraceuticals > Evening primrose oil > Unknown > cyclical mastalgia > Symptom-relief claim > Multiple: primary unresolved
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
The two-center double-blind trial by Pruthi and colleagues randomized 85 women across four groups, but only 41 were assessed at six months. The evening-primrose-oil versus placebo comparison for change in modified McGill breast pain failed with P=0.18. The double-blind factorial trial by Blommers and colleagues randomized 120 women and used an intention-to-treat analysis of pain days at six months; reductions were 12.3% with evening primrose oil versus 13.8% with control oil, P=0.73.
Why this is classified as D (24)
The primary comparison failed in a trial with 85 randomized but only 41 assessed participants, and an independent 120-participant factorial trial also failed with P=0.73. High attrition and conflicting small data keep the rating at D rather than F, with 24 points.
Counterpoint. A supportive bra, a pain diary, standard analgesia when appropriate, and clinical assessment have a more defensible role.
Rejudgment record. Cross-check applied — Treated patient-reported pain as a direct outcome but applied the failed primary between-group comparison among 41 assessed of 85 randomized participants and the independent failed 120-participant intention-to-treat trial
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Reduction in cyclical breast-pain severity over six months | D | The primary between-group modified McGill comparison failed with P=0.18. |
| Reduction in the proportion of days with breast pain | D | The 120-participant intention-to-treat trial found no advantage over control oil, P=0.73. |
| Sustained remission of cyclical mastalgia | ? | A repeat search found no long-term human randomized trial directly testing sustained remission after treatment. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Pruthi S et al. 2010 | Two-center randomized double-blind placebo-controlled pilot trial | 85 randomized; 41 actually assessed at six months | Academic study led by Mayo Clinic | Primary endpoint: change in the modified McGill Breast Pain Questionnaire | The evening-primrose-oil versus placebo comparison failed with P=0.18; within-group P=0.005 was not a between-group effect. | Pivotal direct trial with substantial attrition |
| Blommers J et al. 2002 | Randomized double-blind factorial controlled trial | 120 randomized; all 120 included in the six-month intention-to-treat analysis | Academic institutional research | Change in the percentage of days with breast pain at six months | Pain days fell by 12.3% versus 13.8% with control oil, P=0.73; failed. | Independent negative replication |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-07-24).
Final verification and publication gate: Codex · Evidence date: 2026-07-24 · Corrections: none
Cite this verdict
[Chamgap] Evening primrose oil x relief of cyclical mastalgia — Evidence Grade D·24. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/evening-primrose-oil-cyclical-mastalgia-pain/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.