Saw Palmetto vs Black Cohosh for Perimenopause: What the Evidence Says
Saw palmetto and black cohosh are popular supplements during perimenopause. Compare what each does, the evidence behind them, and safety considerations.
Two Popular Supplements, Very Different Purposes
When you start researching natural supplements for perimenopause, saw palmetto and black cohosh often appear on the same lists. But they are quite different in what they are traditionally used for, how they work, and what the research actually shows. Saw palmetto is primarily associated with androgen-related concerns including hair thinning and libido. Black cohosh has a longer history of use specifically for menopausal symptoms like hot flashes. Understanding what each one is actually meant to do will help you decide whether either is worth trying, and which one is more relevant to your specific symptoms.
What Black Cohosh Is and How It Works
Black cohosh is a plant native to North America. Indigenous peoples used it medicinally for centuries, and it became a widely used remedy in Europe and North America for menopausal symptoms in the 20th century. It is most commonly sold as an extract under brand names like Remifemin. For a long time, black cohosh was assumed to work by mimicking estrogen, but more recent research suggests its active compounds act on serotonin receptors and possibly dopamine pathways rather than directly on estrogen receptors. This distinction matters because it means it may be safer for women who cannot use estrogen-based treatments, though the evidence on this is still evolving. It is primarily studied for hot flashes and night sweats, with some research also looking at mood, sleep, and anxiety.
What the Research Says About Black Cohosh
The evidence for black cohosh is mixed. Some well-designed trials have shown meaningful reductions in hot flash frequency and severity compared to placebo. Others have found no significant benefit. A Cochrane review found that while some studies suggest a modest benefit, the overall evidence is inconsistent and the quality of trials varies. The North American Menopause Society has noted that black cohosh may be worth trying for mild-to-moderate vasomotor symptoms in women who cannot or prefer not to use HRT. Safety concerns have included rare cases of liver toxicity, and women with liver conditions should avoid it. It should not be used for longer than six months without medical advice. It is not recommended for women with hormone-sensitive cancers due to remaining uncertainty about its long-term hormonal effects.
What Saw Palmetto Is and How It Works
Saw palmetto comes from the berries of a palm plant native to the southeastern United States. It has been studied most extensively for benign prostatic hyperplasia in men and is one of the most widely sold herbal supplements in the world. In women, interest in saw palmetto has grown because of its proposed ability to block 5-alpha-reductase, an enzyme that converts testosterone to dihydrotestosterone (DHT). DHT is the form of testosterone most associated with androgenic hair loss. Women experience androgenic hair thinning during perimenopause as estrogen falls and the relative influence of androgens increases. Some women also use saw palmetto for concerns about oily skin and acne linked to androgen sensitivity. There is also limited and weaker research suggesting it may support libido, though the evidence here is very preliminary.
What the Research Says About Saw Palmetto for Women
The evidence for saw palmetto in women is considerably thinner than for men. Most clinical trials have been conducted in men with prostate issues. A small number of studies in women with female pattern hair loss have shown modest benefit, and some practitioners recommend it alongside other treatments for androgenic alopecia. However, the research is not strong enough to make firm conclusions. Saw palmetto does not appear to significantly affect estrogen or progesterone levels, which means it is unlikely to address hot flashes, mood changes, or vaginal symptoms. It is not an anti-estrogenic supplement and is generally considered safe in typical doses, though it can interact with blood thinners and other medications. Gastrointestinal side effects including nausea are the most commonly reported issue.
How to Choose Between Them
The choice really depends on which symptoms you are trying to address. If your main concerns are hot flashes, night sweats, sleep disruption, or mood changes, black cohosh has more relevant research and a longer history of use for those symptoms. It is one of the most studied herbal options for vasomotor symptoms specifically. If your main concerns are hair thinning, changes in scalp oiliness, or possible androgen-related symptoms, saw palmetto is more targeted to that mechanism. Some women choose to use both, as they address different symptom categories and their mechanisms do not directly overlap. However, taking multiple supplements always carries the risk of interactions and side effects, and adding more supplements does not guarantee better results.
Important Considerations Before Starting Either
Neither supplement should be approached as a replacement for medical care or hormone therapy if your symptoms are significantly affecting your quality of life. Both are available without a prescription, but that does not mean they are without risk. Supplement quality is highly variable because they are not regulated with the same rigor as prescription drugs. Look for products with third-party testing certification such as USP, NSF, or ConsumerLab to reduce the risk of contamination or mislabeling. Talk to your doctor before starting either supplement, especially if you take any medications, have liver concerns, or have a personal or family history of hormone-sensitive cancers. Tracking your symptoms before and after starting a supplement will help you judge whether it is actually making a difference.
Related reading
Get your personalized daily plan
Track symptoms, match workouts to your day type, and build a routine that adapts with you through every phase of perimenopause.