Camphor is a bicyclic monoterpene ketone found widely in plants, especially cinnamomum camphora. Topically, camphor is used to relieve pain. It has been used to treat warts, cold sores, hemorrhoids, and osteoarthritis. It has also been applied topically as an analgesic and an antipruritic. It has been used as a counterirritant, and to increase local blood flow. Camphor has frequently been used topically to treat respiratory tract diseases involving mucous membrane inflammation. It is sometimes used topically to treat cardiac symptoms. Camphor is also used topically as an eardrop, and for treating minor burns. In inhalation therapy, camphor is used as an antitussive. Orally, camphor is used as an expectorant, antiflatulent, and for treating respiratory tract diseases. Today, most camphor is synthetic. It is approved by the FDA as a topical antitussive. Camphor is produced synthetically from the oil of turpentine. It has been used for centuries for its medicinal features, in religious rituals, and in cooking. It is no longer used as pesticide. In 1982, the US Food and Drug Administration restricted commercial products intended for medicinal use to contain <11% camphor.