High content in grass and flowers of tansy tannins makes it a valuable astringent anti-inflammatory drugs in nature to the skin and mucous membranesFor many years, tansy has been used as a medicinal herb. Irish folklore of the mid-1800s suggests bathing in a solution of tansy and salt as a cure for joint pain. Bitter tea made with the blossoms of tansy has been effectively used for centuries as an anthelmintic. The dried flowering herb is used for migraine, neuralgia, and rheumatism. Pregnant women should avoid this herb.The herb is tonic, cholagogic, stimulant and emmenagogue. In moderate doses, the plant and its essential oil are stomachic and cordial, being anti-flatulent and serving to allay spasms. In large doses, it becomes a violent irritant, and induces venous congestion of the abdominal organs.