Laudanum is a tincture of opium containing approximately 10% powdered opium by weight (the equivalent of 1% morphine). Reddish-brown and extremely bitter, laudanum contains almost all of the opium alkaloids, including morphine and codeine, and its high morphine concentration makes it a potent narcotic. Laudanum was historically used to treat a variety of ailments, but its principal use was as an analgesic and cough suppressant. Until the early 20th century, laudanum was sold without a prescription and was a constituent of many patent medicines. Today, laudanum is recognized as addictive and is strictly regulated and controlled throughout most of the world.