Phytoestrogens, black cohosh and St. John’s Wort are mentioned in the NICE guidelines as products that may alleviate vasomotor symptoms such as hot flushes and night sweats, but it also mentions that there can be variations in standards between different products. St. John’s Wort, in particular, may interact with certain types of conventional medicines.
Phytoestrogens are naturally occurring substances that are present in plants which have similar but less potent effects to conventional oestrogens. They are divided into 2 main types: isoflavones and lignans. These occur naturally in enriched foods and are also available as a food supplement in health stores. Isoflavones can be found in soybeans, chickpeas, red clover. Lignans can be found in oilseeds such as flaxseeds, bran, vegetables, legumes and fruit.
If taking a supplement, it’s important to get a product that has a traditional herbal registration, as approved by the HPRA (Health Products Regulatory Authority) as this product would have needed to meet certain standards in order to be registered. It’s also important to note that the efficacy of these products would not have been tested in a similar manner to conventional medications via clinical trials. There is no guidance on whether these products should be used in patients with a previous history of hormone-sensitive cancer and there have been reports of liver and kidney toxicity in rare cases.
Scientific studies showing that ginseng, dong quai, wild yam. agnus castus, liquorice root, valerian root, maca and evening primrose oil can improve menopausal hot flushes and night sweats are lacking, although they might improve general well-being and mood. Ginko biloba does not appear to improve hot flushes, but some studies have shown an improvement in cognition and memory.
Acupuncture may improve night sweats, hot flushes, mood irritability and increase general well-being in some women.