Background

Black cohosh (Actaea racemose) is a woodland herb native to North America. The root is used as medicine and is often used for estrogen-related conditions.

In some parts of the body, black cohosh might increase the effects of estrogen. In other parts of the body, black cohosh might decrease the effects of estrogen. Black cohosh should not be thought of as an "herbal estrogen" or a substitute for estrogen.

People commonly use black cohosh for symptoms of menopause, premenstrual syndrome (PMS), painful menstruation, weak and brittle bones, and many other conditions, there is no good scientific evidence to support most of these uses.

Don't confuse black cohosh with blue cohosh or white cohosh. These are unrelated plants.

Safety Safety definitions

When taken by mouth: Black cohosh is possibly safe when taken appropriately for up to one year. It can cause some mild side effects such as stomach upset, headache, rash, and a feeling of heaviness. There is also some concern that black cohosh might cause liver damage in some people. People who take black cohosh should watch for symptoms of liver damage such as dark urine and fatigue.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Black cohosh is possibly unsafe to use when pregnant or breast-feeding. It might increase the risk of miscarriage or affect a nursing infant.

Breast cancer: There is some concern that black cohosh may worsen existing breast cancer. But this concern hasn't been confirmed in scientific research. People who have breast cancer, have had breast cancer in the past, or are at high-risk for breast cancer, should speak with a healthcare professional before using black cohosh.

Hormone-sensitive conditions, including endometriosis, fibroids, ovarian cancer, uterine cancer, and others: Black cohosh acts somewhat like estrogen in the body. There is some concern that it might worsen conditions that are sensitive to estrogen. If you have a condition that could be affected by estrogen, speak with a healthcare professional before using black cohosh.

Liver disease: Black cohosh might cause liver damage in some people. But it isn't clear how often this occurs. Until more is known, people with liver disease should avoid taking black cohosh.

Effectiveness

Dosing & administration

Black cohosh has most often been used by adults in doses of 40-128 mg by mouth daily for up to one year. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Interactions with pharmaceuticals

Atorvastatin (Lipitor)

Interaction Rating=Moderate Be cautious with this combination.

There is concern that black cohosh might harm the liver. Taking black cohosh with atorvastatin might increase the chance of liver damage.

Cisplatin (Platinol-AQ)

Interaction Rating=Moderate Be cautious with this combination.

Cisplatin is used to treat cancer. There is some concern that black cohosh might decrease how well cisplatin works for cancer.

Estrogens

Interaction Rating=Moderate Be cautious with this combination.

Black cohosh might have some of the same effects as estrogen. Taking black cohosh along with estrogen pills might decrease the effects of estrogen pills.

Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates)

Interaction Rating=Moderate Be cautious with this combination.

Some medications are changed and broken down by the liver. Black cohosh might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

Medications moved by pumps in cells (Organic anion-transporting polypeptide substrates)

Interaction Rating=Minor Be watchful with this combination.

Some medications are moved in and out of cells by pumps. Black cohosh might change how these pumps work and change how much medication stays in the body. In some cases, this might change the effects and side effects of a medication.

Medications that can harm the liver (Hepatotoxic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Black cohosh might harm the liver. Some medications can also harm the liver. Taking black cohosh along with a medication that can harm the liver might increase the risk of liver damage.

Interactions with herbs & supplements

Herbs and supplements that might harm the liver: Black cohosh might harm the liver. Taking it with other supplements that can also harm the liver might increase the risk of liver damage. Examples of supplements with this effect include garcinia, greater celandine, green tea extract, kava, and kratom.

Interactions with foods

There are no known interactions with foods.