Complementary therapies

There is some evidence that black cohosh, isoflavones (in red clover) and St John’s wort may relieve vasomotor symptoms during the menopause, but the constituents, quality, purity and safety of the products may not be known.

Women sometimes take these supplements expecting them to be safer than prescribed medicines but in many instances their safety may be worse or unquantified. There are potential interactions between St John’s wort and tamoxifen, anticoagulants and anticonvulsants, for example. Black cohosh may inhibit CYP3A4 and so could potentially increase the risk of adverse effects with drugs metabolised by this enzyme.

Some complementary therapies such as red clover contain constituents with oestrogen-like properties (phytoestrogens), and these are also found in food such as soya. There are many studies looking at the effectiveness of these food substances, but the results are variable and generally show little value. They should not be used in patients with a history of breast cancer.

Bioidentical hormones are offered by private clinics in a mix of plant-derived oestrogens, often together with progesterone and testosterone in quantities based on the results of saliva and/or blood tests. They are formulated as creams, lozenges and vaginal preparations. NICE points out that “the efficacy and safety of unregulated compounded bioidentical hormones are unknown” as they are not subject to the usual regulatory processes for medicines.