Black cohosh for menopause symptoms: what UK sources say about evidence and safety

Black cohosh is one of a number of herbal remedies sold in health shops for symptoms of menopause and perimenopause. The NHS lists the herbal remedies sometimes taken for menopause symptoms as evening primrose oil, black cohosh, angelica, ginseng, St John's wort and red clover. It says red clover contains plant hormones that can act in a similar way to oestrogen, while black cohosh is believed to balance oestrogen and progestogen levels.

People often turn to these products because they want something described as natural, because they cannot or do not want to take HRT, or because their symptoms are affecting sleep, mood and daily life. The NHS describes menopause and perimenopause symptoms as including hot flushes and night sweats, sleep problems, mood changes, poor memory and brain fog, weight gain, vaginal problems and changes to periods, and notes that they are different for everyone.

The NHS says that herbal remedies such as red clover and black cohosh are sometimes sold for symptoms of menopause or perimenopause, but there is very little evidence to show how well they work, or how safe they are. Its page on herbal remedies says these may help with some menopause symptoms, but this is not supported by scientific evidence. Even when there is some supporting evidence, there is uncertainty about the right doses and whether the health benefits last.

The NHS also warns that some herbal remedies and complementary medicines, especially St John's wort, may cause serious side effects if they are taken with other medicines.

The NHS says health shops sell a variety of products to treat menopause symptoms, but they are not tested and regulated in the same way as medicines such as hormone replacement therapy, so it is not known how safe and effective they are. It says it is a good idea to ask a GP or pharmacist for advice if you are thinking about using a complementary therapy.

It adds that these products are often marketed as natural, but that does not necessarily mean they are safe, and that the quality, purity and ingredients cannot always be guaranteed, so they may cause unpleasant side effects. In practice this means that two bottles labelled black cohosh may not contain the same amount of active material, and that a product may not be what it claims to be.

The Specialist Pharmacy Service (SPS), which provides medicines information to NHS professionals, says people with liver disease should be cautious when taking herbal products, as advised by the British Liver Trust, because complementary products may not be dose-adjusted for reduced liver function and could accumulate to toxic levels. It says some herbal products have been associated with drug-induced liver disease up to 3 to 6 months after stopping, for example black cohosh, kava and mistletoe.

If you have liver disease, take medicines that affect the liver or have had abnormal liver tests, discuss any herbal product with your GP or pharmacist before taking it. If you feel unwell while taking any herbal product, seek medical advice. The SPS also notes that herbal products should be avoided in pregnancy unless the benefits outweigh the risks, and that they should be avoided while breastfeeding as advised by the NHS because of insufficient information on how they pass into breast milk.

The SPS says people at higher risk of side effects, interactions or serious treatment failure should generally avoid complementary products, and that complementary products should not replace conventional medicines where that could result in loss of control of a condition or toxicity. It advises that anyone taking complementary products should tell their doctor or pharmacist, so interactions can be checked.

The NHS stresses the same point for menopause remedies: tell your doctor about any medicines, herbal remedies, vitamins or supplements you take.

The NHS says that if you have symptoms of perimenopause or menopause you should talk to a doctor, nurse or pharmacist about HRT and other options. Oestrogen is the main type of HRT and can help manage symptoms; if you have not had a hysterectomy, progestogen is added to protect the womb. Testosterone can improve low libido for some people. If HRT does not work, you cannot take it or you do not want to, other treatments are available.

For hot flushes and night sweats, the NHS says you may be offered cognitive behavioural therapy (CBT), or if that does not help a doctor may suggest clonidine or an antidepressant. If low mood, depression or anxiety is caused by perimenopause or menopause you may be offered antidepressants. The NHS also says bioidentical hormones are not recommended because they are not regulated and it is not clear how safe or effective they are, whereas body identical hormones, which have been regulated, tested and researched, can be prescribed.

The NHS says to contact your GP if you think you have symptoms of menopause or perimenopause and want to know your options, if you have symptoms such as a fast heartbeat, if you still have periods but bleeding has become heavier, or if you have not had a period for 12 months or more and have any vaginal bleeding. Early advice can help reduce the effects of menopause and perimenopause on health, relationships and work.

Menopause assessment and HRT can be arranged through a GP, a practice nurse or a pharmacist on the NHS, with referral to a menopause specialist where needed. Herbal products are bought privately and are not NHS-prescribed for menopause. If you use one, mention it at consultations so it is recorded with your other medicines and so that any interaction can be checked.