Under this name appears a derivative of thymol, corresponding to phenacetin, a derivative of phenol. It occurs in the form of whitish crystals, slightly soluble in water.

Thymacetin possesses properties not unlike phenacetin, its congener. It is analgesic, antipyretic, and antiseptic. By Jolly it has been used successfully in the treatment of hemicrania and congestion of the brain. It has been beneficial in other kinds of neuralgia, and as a hypnotic in wakefulness. It will probably prove useful in asthma, whooping-cough, and other nervous affections. The dose ranges from 2 to 10 grains.