You've started taking black cohosh for hot flashes, and a few weeks later you notice the scale creeping up. Naturally, you wonder: is the supplement to blame? Is black cohosh causing weight gain?
This is one of the most common questions women ask when they begin exploring natural remedies for menopause symptoms. The concern is understandable — you're already dealing with menopause-related weight changes, and the last thing you want is a supplement that makes things worse.
Here's the reassuring short answer: the scientific evidence does not support black cohosh as a cause of weight gain. But there's nuance worth understanding — both about the research and about the real drivers of weight changes during this time of life.
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Black cohosh (Cimicifuga racemosa, also known as Actaea racemosa) is a perennial plant native to North America that has been used for centuries — first by Indigenous peoples and later in Western herbal medicine — to treat a variety of female health conditions. Today it's primarily marketed as a natural remedy for menopause symptoms, particularly hot flashes and night sweats.
It's one of the most widely sold botanical supplements in the United States and Europe, and it's among the most studied herbs for menopause management. According to the National Center for Complementary and Integrative Health (NCCIH), a 2023 review of 22 studies found that black cohosh preparations were potentially beneficial for overall menopause symptoms and showed improvements specifically in hot flashes — though effects on anxiety and depressive symptoms were not clearly demonstrated.
The most definitive answer to this question comes from a rigorous systematic review published in the peer-reviewed journal Climacteric in 2021, authored by a multinational team of researchers. This review was conducted specifically to investigate whether black cohosh causes weight gain in menopausal women. The researchers searched for:
Their conclusion, published on PubMed (PMID 34608830): "This study provides no scientific evidence that the use of Cimicifuga racemosa causes weight gain in menopausal women."
Here are the key findings from that review:
A separate observational study published in Archives of Gynecology and Obstetrics (CIMBOLIC study) similarly found that body weight did not change significantly in women treated with black cohosh, compared to those on menopausal hormone therapy.
The bottom line: based on currently available evidence, black cohosh does not cause weight gain.
Understanding how black cohosh works helps clarify why it's unlikely to affect weight. Despite early speculation that it acted as a phytoestrogen (plant-based estrogen), current research indicates that black cohosh's primary mechanism is quite different.
According to a comprehensive review published in the Journal of Mid-Life Health (2024), black cohosh appears to exert its effects primarily through:
Because black cohosh does not significantly alter estrogen, progesterone, or other metabolic hormones, there is no known biological mechanism by which it would independently cause fat gain or metabolic changes.
When used appropriately, black cohosh may offer relief from several menopause symptoms:
The strongest evidence for black cohosh is for vasomotor symptoms. A meta-analysis of 22 randomized controlled trials involving 2,310 participants found mild to moderate benefits for hot flashes and overall menopausal symptoms compared to placebo. A 2013 randomized clinical trial published in Chinese Medicine found that black cohosh significantly reduced total menopausal symptom scores over 8 weeks.
Some trials suggest black cohosh may improve psychological symptoms associated with menopause — though this effect is not consistent across all studies. A combination product with St. John's Wort appeared to show greater mood benefits than black cohosh alone.
By reducing hot flashes and night sweats, black cohosh may indirectly support better sleep quality — a significant benefit given that sleep disruption is a primary driver of metabolic and weight issues during menopause.
One study found that 40mg daily of black cohosh may reduce the size of uterine fibroids by up to 30% over three months, though this evidence is preliminary.
While black cohosh appears safe for short-term use (up to 12 months based on clinical trials), there are important safety considerations every woman should know:
Black cohosh can cause:
The most serious safety signal associated with black cohosh is potential liver damage. According to NCCIH, there have been reports of liver problems — including hepatitis and liver failure — associated with black cohosh supplements. However, investigation has suggested that many of these cases involved products adulterated with other herbs, not pure black cohosh itself. A review found that up to 42% of commercial black cohosh products may be adulterated.
Do not take black cohosh if you: have liver disease, are taking medications that affect the liver, are pregnant, or are breastfeeding.
Although black cohosh does not appear to act as a true estrogen, women with a personal or family history of hormone-sensitive cancers (breast, uterine, ovarian) should consult their healthcare provider before using it, as the evidence on safety in this population is mixed. Several cancer organizations recommend avoiding black cohosh if you have a history of cancer.
Black cohosh supplements are not FDA-approved or regulated for safety and potency. This means that products may vary significantly in purity and concentration. If you choose to use black cohosh, look for products from reputable manufacturers that use standardized extracts with third-party testing, and discuss the decision with your healthcare provider.
If you've noticed weight gain around the time you started taking black cohosh, the much more likely explanation is that the weight gain is driven by the hormonal and metabolic changes of perimenopause or menopause itself — not by the supplement.
As noted by GoodRx: "Weight changes don't seem to be a side effect of black cohosh. But weight changes can happen during perimenopause and menopause as your hormone levels change."
The timing correlation — starting a supplement and noticing weight changes — can feel meaningful, but the underlying driver is almost certainly the hormonal transition your body is undergoing, independent of any supplement. Menopause-related weight gain often accelerates in the perimenopausal years precisely because this is when women are most likely to seek symptom relief through supplements like black cohosh.
Understanding this distinction is empowering, because it means the weight gain has identifiable, addressable causes — and a supplement is unlikely to be among them.
While black cohosh may offer symptom relief for some women, nutrition is a powerful tool for managing both menopause symptoms and weight simultaneously — without the uncertainty of supplement regulation or the potential for side effects.
Soy foods (edamame, tofu, tempeh, miso) contain isoflavones — plant compounds that interact weakly with estrogen receptors. Multiple studies suggest that regular soy consumption is associated with reductions in hot flash frequency and severity, particularly in populations with high soy intake. Unlike black cohosh, the safety profile of whole soy foods is well-established.
Flaxseeds are rich in lignans, another class of phytoestrogens with emerging evidence for hot flash reduction. Ground flaxseed (1-2 tablespoons daily) can easily be incorporated into smoothies, oatmeal, or yogurt.
A Mediterranean-style diet reduces systemic inflammation, which drives many menopause symptoms. Research suggests women following Mediterranean dietary patterns experience fewer and less severe hot flashes.
Stabilizing blood sugar through adequate protein intake and avoiding refined carbohydrates and sugar has been shown to reduce hot flash frequency — because blood sugar spikes and crashes can trigger vasomotor symptoms.
Omega-3s from fatty fish (salmon, sardines, mackerel) or flaxseed oil reduce inflammation and support mood and brain health. Some research suggests regular omega-3 intake may reduce hot flash severity.
Take Your Free 2-Minute Quiz to discover which foods your body needs most right now to manage menopause symptoms and support a healthy weight.
Based on available evidence, no. A 2021 systematic review covering 31 clinical trials involving 1,839 women found no scientific evidence that black cohosh causes weight gain in menopausal women. Weight gain occurring around the time of black cohosh use is almost certainly due to the hormonal changes of perimenopause and menopause themselves, not the supplement.
Current research indicates that black cohosh works primarily through serotonergic and dopaminergic pathways, not through estrogen receptors or metabolic hormones. It does not significantly alter circulating estrogen, progesterone, or metabolic hormones in a way that would cause weight gain. It should not be thought of as an "herbal estrogen."
Clinical trials have used black cohosh safely for up to 12 months. Long-term safety data beyond this period is limited. The primary safety concern is potential liver toxicity, though this appears most often associated with adulterated products rather than pure black cohosh. Women with liver conditions, hormone-sensitive cancers, or those taking liver-metabolized medications should consult their healthcare provider before using black cohosh.
Evidence-based dietary approaches for menopause symptoms include: soy foods (isoflavones for hot flashes), ground flaxseed (lignans for vasomotor symptoms), Mediterranean-style diet (reduces symptom severity and frequency), omega-3 fatty acids (supports mood and reduces inflammation), and adequate protein (stabilizes blood sugar, which influences hot flash frequency). These food-based approaches have the added benefit of supporting weight management simultaneously.
At Balance Bags, we believe the most sustainable approach to menopause symptoms — including weight management — starts with nutrition, not supplements. Our certified nutritionists build personalized, hormone-smart meal plans that incorporate the evidence-based foods and nutritional strategies that support hormonal balance, reduce hot flashes, stabilize mood, and protect against the weight gain that menopause can bring.
You don't have to rely on supplements when food can be your medicine.
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These statements have not been evaluated by the Food and Drug Administration. Balance Bags is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult your healthcare provider before making changes to your diet, especially if you have a medical condition or take medication.
