Evening primrose oil for menopause weight gain: what is the evidence?
Clinical review pending
Can evening primrose oil affect weight and hot flashes during menopause? What studies show, which questions remain open and what the alternatives are.
Evening primrose oil is recommended for menopausal complaints ranging from hot flashes to weight gain, and health food stores and wellness blogs promote it accordingly. The research on its effect on weight, however, is far less convincing than the marketing.
What does evening primrose oil contain?
Evening primrose oil is pressed from the seeds of Oenothera biennis, a plant native to North America. The oil contains about 74% linoleic acid and 9% gamma-linolenic acid (GLA), both omega-6 fatty acids. The body converts GLA into dihomo-gamma-linolenic acid (DGLA), which in turn gives rise to prostaglandin E1, a signaling molecule with anti-inflammatory effects.
This metabolic pathway influences immune responses and may reduce inflammatory signals at the cellular level. Prostaglandin E1 does not, however, mimic estrogen, does not regulate appetite hormones such as leptin or ghrelin, and does not directly affect insulin sensitivity or glucose metabolism in any way that would meaningfully change weight.
How does menopause change weight and metabolism?
The fall in estrogen during menopause sets off a series of metabolic changes. Estrogen influences where the body stores fat, and as levels drop, fat distribution shifts from the hips and thighs to the abdomen. Visceral fat builds up around the internal organs, is metabolically active and raises cardiovascular risk.
Basal metabolic rate declines during this transition. With lower estrogen, muscle mass is harder to maintain. Because muscle tissue burns more energy at rest than fat tissue, daily energy needs can fall as a result. Weight gain is then possible even if your diet stays the same. Keeping your weight stable may take less energy intake or more physical activity than before menopause.
Evening primrose oil does not counteract these mechanisms. It does not replace estrogen, preserve muscle mass or raise metabolic rate.
What research shows about evening primrose oil and weight
There are only a few clinical data on evening primrose oil and weight, and they are inconsistent. One double-blind controlled study found no significant difference in weight loss between people taking evening primrose oil and people taking a placebo. An older study looked specifically at evening primrose oil in people with obesity that was difficult to treat and concluded that any anti-obesity effect of the oil was clinically insignificant. Source
Most Western diets already contain far more omega-6 than omega-3 fatty acids, so adding more omega-6 through evening primrose oil is unlikely to improve that ratio. Studies with moderate metabolic effects typically used high doses and examined things like liver fat accumulation or fatty acid oxidation under controlled conditions. The fatty acid oxidation study cited here was done in rats. Such effects do not necessarily translate into meaningful changes in body weight or body composition in people under everyday conditions. Source
Evening primrose oil and hot flashes
Some studies suggest that evening primrose oil may reduce the intensity of hot flashes or improve quality of life in women going through menopause, while other well-designed studies found no effect. A 2024 systematic review and meta-analysis found that evening primrose oil, used short term (under 6 months), may slightly reduce the severity of hot flashes, but it found no significant difference in their frequency or duration compared with placebo.
Why menopausal weight gain varies so much between women
Genetics plays a major role in how the body responds to falling estrogen. Some women carry genetic variants that affect fat storage, sensitivity to appetite hormones and metabolic rate. Body composition before menopause matters too. Women who enter menopause with more muscle mass tend to have a higher basal metabolic rate.
Past dieting can also shape what happens to weight later on. Repeated cycles of losing and regaining weight can lower metabolic rate through metabolic adaptation, which makes it harder to lose weight or keep it off during menopause. Women with greater insulin resistance before menopause tend to build up more visceral fat during the transition. Measuring insulin can help put an individual risk profile in context.
Sleep quality, stress and hormonal changes interact and influence how weight develops. Poor sleep raises cortisol, which promotes the buildup of visceral fat. Chronic stress has similar effects. These factors work through mechanisms that taking evening primrose oil does not influence.
What helps with weight changes?
The most effective measures target the mechanisms that drive weight gain during menopause. Strength training preserves muscle mass, which keeps metabolic rate up. Protein intake becomes increasingly important, because it supports muscle protein synthesis and increases fullness.
Metabolic markers can make changes in the body visible. Hemoglobin A1c reflects average blood sugar over three months. Triglycerides give clues about how the body handles dietary fat and carbohydrates. High-sensitivity C-reactive protein measures systemic inflammation, which increases during menopause and correlates with the buildup of visceral fat.
For women with significant symptoms, hormone replacement therapy remains the best-supported treatment. Low-dose estrogen and progesterone can reduce hot flashes, preserve bone density and help prevent some of the metabolic changes that lead to weight gain.
Tracking metabolic health over time
The scale alone does not show what is happening in your metabolism. Weight can stay the same even while muscle mass falls and visceral fat rises. That kind of shift in body composition increases health risk.
Fasting glucose, insulin and hemoglobin A1c give clues about changes in glucose metabolism. Testosterone and sex hormone-binding globulin help put hormonal balance in context. Changes in thyroid function can also have a substantial effect on weight at this stage of life. Repeating measurements a few months apart makes trends visible and can help you adjust your approach.
Frequently asked questions
Does evening primrose oil cause weight gain?
There is no consistent evidence linking evening primrose oil to weight gain. Clinical studies comparing evening primrose oil with placebo have found no significant differences in weight change. The omega-6 fatty acids in evening primrose oil are involved in inflammatory processes, not in the hormonal or metabolic mechanisms that drive weight gain during menopause.
Can evening primrose oil help with weight loss during menopause?
The studies so far do not show a clinically relevant benefit of evening primrose oil for weight loss. Studies that looked specifically at evening primrose oil in obesity found that any effects on weight were clinically insignificant. Weight gain during menopause is caused by falling estrogen and metabolic changes that evening primrose oil cannot counter.
Is evening primrose oil better than hormone replacement therapy for menopausal symptoms?
No. Hormone replacement therapy is considerably more effective than evening primrose oil at treating menopausal symptoms. While some studies suggest that evening primrose oil may slightly reduce the intensity of hot flashes, the results are inconsistent. Hormone therapy replaces the missing estrogen, and there is solid evidence for its symptom relief and metabolic effects.
How much evening primrose oil should you take during menopause?
Most studies that examined evening primrose oil for menopausal symptoms used doses between 500 mg and 2,000 mg a day. Because its effectiveness has not been consistently shown, however, there is no established therapeutic dose. Talk to a doctor about the appropriate dose before using it.
Does evening primrose oil contain estrogen?
No. Evening primrose oil contains no estrogen or phytoestrogens. It contains omega-6 fatty acids, mainly linoleic acid and gamma-linolenic acid. These fatty acids are converted into anti-inflammatory compounds called prostaglandins, but they neither mimic estrogen nor replace falling estrogen levels during menopause.
What are the best over-the-counter options for weight management during menopause?
No over-the-counter supplement has convincing evidence that it prevents weight gain during menopause. The most effective approaches include strength training to preserve muscle mass, enough protein, and tracking metabolic markers to adjust what you do. Some women benefit from magnesium for sleep quality or vitamin D for metabolic health, but these are about correcting specific deficiencies, not directly about weight loss.
What are the alternatives to evening primrose oil for weight gain?
Strength training, enough protein and a diet guided by metabolic markers are the best-supported strategies for weight management during menopause. Strength training preserves muscle mass and helps maintain resting metabolic rate. Protein supports muscle protein synthesis and fullness. For women with significant symptoms, HRT remains the best-supported option: low-dose estrogen and progesterone can help limit the metabolic changes that lead to weight gain. Tracking HbA1c, triglycerides and hs-CRP provides objective data to guide diet and lifestyle decisions.
Can evening primrose oil ease menopausal symptoms that indirectly lead to weight gain?
The findings on evening primrose oil (EPO) for hot flashes are mixed. A 2024 meta-analysis found that, compared with placebo, it may slightly reduce the severity of hot flashes in the short term, but not their frequency or duration, which leaves its indirect role in weight management unclear. Poor sleep from night sweats raises cortisol levels and dysregulates hunger hormones such as leptin and ghrelin, which contributes to weight gain; if evening primrose oil improves sleep somewhat, it could offer an indirect benefit. The effects observed, however, appear to be small and short-lived. Evening primrose oil does not act against falling estrogen, insulin resistance or muscle loss. Current evidence is not sufficient to recommend evening primrose oil specifically for weight changes during menopause.
Sources and references
Haslett C, Douglas JG, Chalmers SR, Weighhill A, Munro JF (1983). A double-blind evaluation of evening primrose oil as an antiobesity agent. International journal of obesity, 7(6), 549-53. https://pubmed.ncbi.nlm.nih.gov/6360923/ Publication
Takada R, Saitoh M, Mori T (1994). Dietary gamma-linolenic acid-enriched oil reduces body fat content and induces liver enzyme activities relating to fatty acid beta-oxidation in rats. The Journal of nutrition, 124(4), 469-74. https://doi.org/10.1093/jn/124.4.469 Publication
Thevi T, De S, Soe HHK (2024). Evening Primrose Oil for Menopause Hot Flashes: Systematic Review and Meta-Analysis. Journal of menopausal medicine, 30(3), 127-134. https://doi.org/10.6118/jmm.23038 Publication
Timoszuk M, Bielawska K, Skrzydlewska E (2018). Evening primrose (Oenothera biennis) biological activity dependent on chemical composition. Antioxidants, 7(8), 108. https://doi.org/10.3390/antiox7080108 Publication
Lovejoy JC, Champagne CM, de Jonge L, Xie H, Smith SR (2008). Increased visceral fat and decreased energy expenditure during the menopausal transition. International Journal of Obesity, 32(6), 949-958. https://doi.org/10.1038/ijo.2008.25 Publication