Heroin (INN: diacetylmorphine, BAN: diamorphine) is a semi-synthetic opioid synthesized from morphine, a derivative of the opium poppy. It is the 3,6-diacetyl ester of morphine (hence diacetylmorphine). The white crystalline form is commonly the hydrochloride salt diacetylmorphine hydrochloride, however heroin freebase may also appear as a white powder.