Black Cohosh Uses and Side Effects

Black cohosh is an herbal remedy used for hot flashes, night sweats, and other menopausal symptoms. Sometimes it is used for tinnitus (ear ringing), heart palpitations, and other conditions, too. There's limited research evidence, and more study is needed to understand whether and how black cohosh increases estrogen levels and treats menopause symptoms.

Black cohosh (also known as Cimicifuga racemosa or Actaea racemosa) is a member of the buttercup family and a perennial herb traditionally used by Native Americans for medicinal purposes. It's believed to contain phytoestrogens (plant-based estrogens).

This article explores some of the scientific evidence on black cohosh and its potential uses. It also covers dosage, side effects, precautions, interactions, and storage information.

What Is Black Cohosh Used For?

Black cohosh is probably best known as a potential treatment for symptoms of menopause and other ailments that affect the female reproductive system. Although results are mixed and not definitive, some research studies suggest black cohosh may be used to treat certain health conditions.

Below is a look at scientific evidence surrounding various potential uses of black cohosh, including what's known on the benefits of phytoestrogens. Keep in mind that supplement use should be discussed with a registered dietitian (RD), pharmacist, or other healthcare provider. No supplement is intended to treat, cure, or prevent disease. 

Menopausal Symptoms

It's not exactly known why or how black cohosh may alleviate menopausal symptoms. While some studies have shown positive effects of the herb, others have found black cohosh to have little to no use in treating symptoms of menopause.

In one study, researchers compared black cohosh with evening primrose oil to see if either was able to relieve hot flashes, a common vasomotor side effect of menopause. At the end of eight weeks, both herbs showed beneficial effects. However, black cohosh was said to improve both hot flashes and quality of life better than evening primrose oil.

However, other research has found no association between black cohosh use and the relief of symptoms such as hot flashes. Black cohosh showed no benefit in studies of its effect on cognitive function in menopausal people.

Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common hormonal imbalance that affects many women and can cause acne, infertility, mood swings, and other issues.

Some studies have evaluated the potential use of black cohosh in PCOS, specifically when it comes to infertility, although research is lacking in this area.

One systematic review looked at whether black cohosh could be used to induce ovulation and improve pregnancy rates in people assigned female at birth with PCOS. The researchers determined there was not enough high-quality data to support black cohosh's use for this purpose.

More thorough and better-designed research is needed to understand the relationship between black cohosh and PCOS.

Other Uses

The herb is also commonly used for:

• Night sweats
• Vaginal dryness
• Heart palpitations
• Tinnitus
• Vertigo (spinning, dizzying sensation)
• Sleep disturbances
• Nervousness
• Irritability

Although people may use black cohosh for these and other health issues, there is not enough supportive research. Higher-quality studies are needed before determining whether black cohosh is an effective treatment for these conditions.

What Are the Side Effects of Black Cohosh?

Although rare, you may experience side effects when using black cohosh. These side effects may be mild or severe.

Common Side Effects

Generally, black cohosh is thought to be safe. But mild side effects are possible.

Common side effects of black cohosh may include:

• Upset stomach
• Cramping
• Headache
• Rash
• A feeling of heaviness
• Vaginal spotting or bleeding
• Unintended weight gain

Typically, side effects go away once you stop taking the substance. However, if side effects persist or are concerning, you should speak with a healthcare provider.

Severe Side Effects

In extremely rare cases, black cohosh use has been reported to cause liver damage (including hepatitis). However, there is some thought that black cohosh itself may not be to blame, as some other products or contaminants in supplements may be the cause of the liver damage.

Signs of liver damage may include:

• Abdominal pain
• Dark urine
• Jaundice (yellowing of the skin and whites of the eyes)

Stop using black cohosh and seek medical attention if you notice these and other signs of liver damage.

Who Should Avoid Black Cohosh?

Some people may need to take extra precautions when using black cohosh.

There is not enough information available to know if black cohosh is safe for people who are pregnant or nursing. If you are pregnant or nursing, talk with your healthcare provider before using black cohosh.

You should also avoid black cohosh if you have:

• A liver disorder
• A hormone-sensitive condition (like breast cancer)
• An allergy to plants in the buttercup (Ranunculaceae) family

It should also be noted that long-term studies on black cohosh are lacking. Not enough is known about the safety of taking black cohosh for longer than six months.

Dosage: How Much Black Cohosh Should I Take?

Black cohosh dosage has not been standardized. This means that there are varying doses of black cohosh, and how much you take may depend on the reason you're using it or the brand you use.

Black cohosh studies have used a wide range of doses, anywhere from 8 milligrams (mg) to 160 mg or more per day.

Because dosing has varied so much in research, it's difficult to determine a recommended dosage for everyone. Carefully read the black cohosh supplement label.

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs. 

Interactions

Black cohosh may interact with certain medications, supplements, or foods. However, extensive research needs to be done in this area, as not enough is known regarding potential interactions with black cohosh.

There is some preliminary evidence to suggest that black cohosh may interact with the following medications:

• Pacerone (amiodarone)
• Allegra (fexofenadine)
• Diabeta, Glynase (glyburide)
• Statin medicines, such as Lipitor (atorvastatin) and Crestor (rosuvastatin)

If you're taking these medications, check with your healthcare provider before using black cohosh.

Otherwise, black cohosh is thought to have a low likelihood of interacting with other medications, supplements, or foods. Still, more research is needed.

How to Store Black Cohosh

Store black cohosh supplements in a cool, dry place. They should also be kept out of direct sunlight. Proper storage will help ensure shelf-life. Take precautions to keep black cohosh out of reach of small children and pets.

Discard black cohosh supplements that have passed their expiration date.

Similar Supplements

There are supplements and herbs on the market that have been researched for uses similar to black cohosh:

• Red clover: Although research results have been conflicting, red clover may help alleviate certain menopausal symptoms, like hot flashes. One meta-analysis found red clover caused a significant reduction in daily hot flashes in perimenopausal and postmenopausal women.
• Inositol: A type of sugar found in the body, inositol may also be used in supplement form to help treat PCOS. However, additional studies are needed to confirm the findings and determine an appropriate dosage.
• Sea buckthorn oil: Like black cohosh, sea buckthorn oil has been studied for its potential uses in vaginal dryness. In one study, it showed beneficial effects on vaginal health.
• Vitex: Vitex (also known as chaste berry) is an herbal remedy that may reduce the incidence of night sweats. One small study on menopausal women found that vitex supplementation alleviated certain menopause symptoms, including night sweats.

There may be additional supplements that work in ways similar to black cohosh. However, you should typically only take one supplement at a time for a given reason. Talk with your healthcare provider about which supplements are best for you.

Sources of Black Cohosh and What to Look For

The best way to get all the nutrients your body needs is through a well-balanced diet. However, sometimes supplements and herbs may be recommended to you for various reasons. There are a few things to remember when searching for black cohosh supplements.

Food Sources of Black Cohosh

Black cohosh is not found in any foods. However, some people use dried black cohosh to make tea. Typically, though, certain parts of the black cohosh plant are used to make herbal remedies. You can find these remedies in many forms.

Black Cohosh Supplements

Black cohosh is sold as capsules, tablets, gummies, and tinctures. You can also find dried black cohosh roots.

It is recommended that you look for supplements that contain black cohosh roots or rhizomes as these are thought to be the medicinal parts of the plant. Most black cohosh supplements are naturally vegan and gluten-free but check the product label regarding these and other diet restrictions you may have.

Summary

Black cohosh is an herb that may be used to treat various health conditions, most of which affect people assigned female at birth.

Despite its long use in traditional medicine, scientific evidence is conflicting regarding its use in relieving menopause symptoms like hot flashes, vaginal dryness, and night sweats.

Side effects are rare but possible when taking black cohosh, and certain people should take extra precautions. Talk with your healthcare provider before trying black cohosh to ensure it is right for you.