Yarrow (Achillea millefolium) is a flowering herb used for centuries to ease digestion and calm a troubled stomach. People take the aerial parts as tea, a tincture, or in capsules.
Some turn to yarrow when the seasons change to help the body’s defenses. Avoid it if you are allergic to ragweed, daisies, or other Asteraceae plants. Yarrow can thin the blood, so stop taking it before surgery and do not combine it with anticoagulant drugs. Do not use during pregnancy.