Yarrow has been credited by scientists with at least minor activity on nearly every organ in the body. Early Greeks used the herb to stop haemorrhages. Yarrow also has antiseptic action against bacteria.
Some people call it knight's milfoil, a reference to yarrow's ability to stop bleeding and promote healing of wounds. In fact, yarrow is often used in herbal remedies. designed to treat heavy bleeding from menstrual periods, bleeding ulcers and more. In addition to its antispasmodic activity, the herb contains salicylic acid (a compound like the active ingredient in aspirin) and a volatile oil with anti-inflammatory properties, making it useful to relieve pain associated with gynecologic conditions, digestive disorders, and other conditions.
Sinus infections and coughs with sputum production may be improved by yarrow, especially when mixed with equal parts goldenseal. Note that a cough with ample sputum production may be a sign of bronchitis or pneumonia and requires the attention of a physician. Yarrow's astringent action is helpful in some cases of allergy, in which watery eyes and nasal secretions are triggered by pollen, dust, molds. Yarrow also has long been used to promote sweating in cases of colds, flu, and fevers, thus helping you get over simple infections.
Some people chew the fresh leaves to relieve toothache Yarrow is applied to the skin to stop bleeding from haemorrhoids; for wounds; and as a sitz bath for painful, lower pelvic, cramp-like conditions in women. In combination with other herbs, yarrow is used for bloating, intestinal gas (flatulence), mild gastrointestinal (GI) cramping, and other GI complaints.
Don’t take yarrow by mouth if you are pregnant. It is believed to affect the menstrual cycle and might cause a miscarriage.