Use of Yarrow in Fevers, including Covid

Yarrow (Achillea millefolium) is a most useful and versatile herb which has found much favour in herbal traditions in Europe and throughout many other parts of the world from Iran to South America. It is a plant bestowed with a plethora of active compounds and as such, might be expected to have multiple physiological effects. Indeed, its use for the amelioration of a wide range of conditions would support this contention. These include hemorrhoids, headache, bleeding disorders, bruises, cough, influenza, pneumonia, kidney stones, high blood pressure, menstrual disorders, fever, rheumatoid arthritis, gout, osteoarthritis, viral illnesses, cystitis, digestive and skin problems. But in this article, I am focussing on Yarrow’s traditional role in treating fevers. It is often used with elderflower and peppermint as a tea to “manage a fever”. But is there any scientific evidence to support this? 

There are a number of key properties of Yarrow which contribute to its value as a herb for fevers. The first is its anti-viral property, which has been shown in cell culture for the virus causing Newcastle disease in chickens and for the virus causing Covid-19 (PMID: 35639782).  Secondly, yarrow is reputed to be an excellent diaphoretic; promoting blood flow to the skin and stimulating sweating. At least one Iranian animal study supports this, showing that the herb enhances temperature reduction in fevers. Thirdly, enhancing (through increased urination or diuresis) the removal of end-products of metabolism (loosely termed ‘toxins’), which accumulate rapidly in the body following viral infection due to cell breakdown. In this context Yarrow’s marked diuretic properties have been reported in laboratory animals by Brazilian researchers. This ‘rounded’ amalgamation of physiological actions is common to a number of herbal remedies, but it is outstanding in Yarrow and is a result of the great complexity in its components. 

Ann Walker PhD FCPP MNIMH RNutr, Herbal Practitioner and Nutritionist, Course Director, Discovering Herbal Medicine: www.newvitalitytuition.com