Black cohosh has the strongest track record among herbs studied for hot flashes, with multiple clinical trials showing it can reduce both the frequency and intensity of episodes within 4 to 12 weeks. But the full picture is more nuanced than any single recommendation. Several herbs have been tested in clinical trials, and the evidence ranges from genuinely promising to essentially useless. Here’s what the research actually shows.
Black Cohosh: The Most Studied Option
Black cohosh is a flowering plant native to North America that has been used for menopausal symptoms longer than almost any other herbal remedy. It works differently than many people assume. Rather than mimicking estrogen, it appears to act on serotonin receptors in the brain, which play a role in temperature regulation. It also has activity related to dopamine and GABA, two brain chemicals involved in mood and stress response.
Clinical trials have consistently shown that black cohosh reduces hot flashes and night sweats. In one trial, women taking a standardized extract for 12 weeks experienced a measurable decrease in hot flash frequency. Another trial found it improved vasomotor symptoms (hot flashes and sweating) as well as sleep, mood, and physical complaints over 4 to 8 weeks. A 2020 trial even found that black cohosh improved menopausal symptoms at rates comparable to conventional hormone therapy. It has also shown promise for breast cancer patients dealing with hot flashes while on tamoxifen.
Most studies use standardized extracts containing about 2.5% triterpenes, the compounds believed to be responsible for its effects. You’ll typically find these sold as tablets or capsules, with treatment periods in studies lasting 8 to 12 weeks before full benefits are seen.
Sage Leaf: Fast-Acting but Less Proven
Sage is an interesting option because it appears to work faster than black cohosh. In a head-to-head comparison, sage extract reduced hot flash intensity after just one week, while black cohosh took four weeks to show similar effects on severity. A 2023 meta-analysis of four clinical trials confirmed that sage significantly reduced the frequency of hot flashes compared to placebo.
Beyond hot flashes specifically, one trial found that sage extract improved a wide range of menopausal symptoms. Scores for sleep disturbances, muscle and joint pain, depression, anxiety, and nervousness all dropped significantly in the sage group compared to controls. The overall body of research is smaller than what exists for black cohosh, but the results so far are encouraging. Sage is typically taken as a tablet made from dried leaf extract, though some women use it as a strong tea.
Red Clover: Moderate Relief From Isoflavones
Red clover contains isoflavones, plant compounds that weakly mimic estrogen in the body. In a randomized controlled trial, women taking 80 mg of red clover isoflavones daily for 12 weeks experienced a 44% reduction in hot flashes compared to placebo. That’s a meaningful difference, though not as dramatic as what prescription treatments typically achieve.
The 80 mg dose used in research is important context. Many supplements on the market contain lower amounts, which may explain why some women report little benefit. If you’re considering red clover, check the isoflavone content on the label rather than just the total milligrams of red clover extract.
Herbs With Weak or No Evidence
Maca Root
Maca root, a plant from the Peruvian Andes, has generated interest for menopausal symptoms. A systematic review found that all the randomized trials showed favorable effects on menopausal symptom scores. However, the reviewers concluded the evidence was too limited to draw firm conclusions, citing too few trials, small sample sizes, and inconsistent study quality. It’s not clear which compounds in maca might be responsible, and more rigorous testing is needed before it can be recommended with any confidence.
Dong Quai
Dong quai is widely used in traditional Chinese medicine, almost always as part of multi-herb formulas. When tested on its own in a 24-week randomized trial, it performed no better than placebo. There was no significant difference in the number of hot flashes, overall menopausal symptom scores, or any hormonal measures. Dong quai may have value within complex herbal blends, but as a standalone remedy for hot flashes, the evidence simply isn’t there.
What the Official Guidelines Say
The North American Menopause Society issued its most recent position statement in 2023, and its conclusion may surprise you: it does not recommend herbal remedies for hot flashes. The panel reviewed the available literature and categorized supplements and herbal remedies as “not recommended” based on Level I and II evidence, meaning there is either good evidence of limited effectiveness or the evidence is inconsistent. Soy foods, soy extracts, and the soy metabolite equol were also placed in the “not recommended” category.
This doesn’t mean these herbs are dangerous or that no woman will benefit from them. It means the evidence, when held to the strict standards used for medical guidelines, isn’t strong or consistent enough for a blanket recommendation. Many women do report meaningful improvement, and the gap between individual experience and population-level evidence is real.
Safety Considerations
Black cohosh has a generally good safety profile in clinical trials. Across studies involving more than 1,200 patients, no cases of liver injury were reported during treatment. However, more than fifty cases of liver damage have been linked to products labeled as black cohosh outside of clinical trials. In several of those cases, the products were later found to contain different plant species entirely, not actual black cohosh. The current understanding is that genuine black cohosh is not inherently toxic to the liver, but mislabeled or adulterated products pose a real risk. Buying from reputable brands that use third-party testing reduces this concern significantly.
For women with a history of estrogen-sensitive breast cancer, soy and red clover deserve extra thought. The American Cancer Society notes that soy foods appear safe and may even slightly reduce breast cancer risk, but it does not recommend soy supplements for cancer prevention. Supplements can contain far higher concentrations of isoflavones than food sources, and the effects of those concentrated doses aren’t well understood. Whole soy foods like tofu and edamame are a different story from isoflavone capsules.
Sage and maca have not raised significant safety concerns in studies to date, though research on both is limited compared to black cohosh. As with any supplement, quality varies enormously between brands, and herbal products are not regulated with the same rigor as prescription medications.
Choosing the Right Herb for You
If you’re looking for the herb with the most clinical support, black cohosh is the clear front-runner. It targets the symptom most women find unbearable (hot flashes and night sweats) and has a plausible biological mechanism through serotonin pathways. Expect to use it for at least 4 to 8 weeks before judging whether it’s working.
Sage may be worth trying if you want faster initial relief or if black cohosh hasn’t helped. Red clover is a reasonable option if you’re comfortable with plant-based estrogen compounds and want a moderate effect. Skip dong quai as a standalone remedy, and treat maca as a maybe rather than a proven solution.
Keep in mind that hot flash severity varies enormously between women. Some experience mild warmth a few times a week, while others have drenching episodes dozens of times a day. Herbs tend to work best for mild to moderate symptoms. Women with severe, life-disrupting hot flashes may find that herbal options take the edge off without fully resolving the problem.