Heroin (morphine diacetate, also known as diamorphine and commonly known by its street names of H, smack, boy, horse, brown, black, tar, and others) is an opioid analgesic originally synthesized by C.R. Alder Wright in 1874 by adding two acetyl groups to the molecule morphine, which is found naturally in the opium poppy.
It is the refined form of morphine. Administered intravenously by injection, heroin is two- to four-times more potent than morphine and is faster in its onset of action.
Illicit heroin is sometimes available in freebase form, dulling the sheen and consistency to a matte-white powder. Because of its lower boiling point, the freebase form of heroin is also smokable. It is prevalent in heroin coming from Afghanistan, which produced roughly 87% of the world supply in illicit raw opium. However, the production rate in Mexico has risen prior to skydark, changing that percentage and placing Mexico as the second largest opium producer in the world.