Cowhage consists of the hairs attached to the fruit of Mucuna pruriens, DC. (N.O. Leguminosae), a climbing plant growing in Tropical Africa, India, and America. The fruit is a curved, blackish-brown legume, 5 to 10 centimetres long and 10 millimetres wide, containing four to six seeds, and covered with stiff, yellowish-brown hairs. These hairs detached from the fruit form the commercial drug. The drug has the appearance of a loose, yellowish-brown, felted mass of hairs, intermingled with occasional black fragments of the pericarp. The hairs are about 2 to 3 millimetres long, one-celled, thin-walled, and sharply pointed, and bear numerous minute recurved prominences.
Constituents.—The hairs contain a little tannin or a brownish substance of tannoid nature.
Action and Uses.—Cowhage was formerly employed as a vermifuge, its action in this respect being entirely mechanical, the sharp hairs penetrating the worm, and allowing its expulsion. The dose is mixed with honey or treacle, and taken on three or four successive mornings, followed finally by a dose of castor oil. An ointment of cowhage (1 in 60) has been used as an external irritant and rubefacient.
Dose.—6 to 40 decigrams (10 to 60 grains).