Yarrow (Achillea millefolium) has a long history of traditional use in various cultures for its medicinal properties, especially in the context of sweat baths and inducing perspiration. In Native American and European herbal traditions, yarrow was commonly included in sweat bath rituals to promote sweating and support the body’s natural detoxification processes. The herb is considered a diaphoretic, meaning it encourages sweating, which is believed to help reduce fevers and cleanse the skin and body of impurities. Historical records indicate that yarrow was added to hot water baths or placed on the stones in sweat lodges to help open pores and stimulate circulation.

While there is a wealth of ethnobotanical evidence supporting yarrow’s use in sweat baths, modern scientific research on its diaphoretic action in humans is limited. Some phytochemical studies have identified compounds in yarrow, such as flavonoids and volatile oils, which may contribute to its traditional diaphoretic effects. However, clinical trials validating its effectiveness for inducing sweating are lacking. Thus, its use in sweat baths is primarily justified by traditional knowledge and historical practice, rather than rigorous scientific validation.