The resulting liquid contains unpurified cocaine alkaloids and may additionally contain waxy material from the leaves. This waxy material can be removed by heating and then cooling the mixture, a process that solidifies the unwanted wax.

Data has shown that people high on marijuana show the same lack of coordination on standard "drunk driver" tests as do people who have had to much to drink.

In the U.S.A the Harrison Narcotics Tax Act was passed in 1914 to control the sale and distribution of heroin and other opiates. The law did allow heroin to be prescribed and sold for medical purposes. In particular, recreational users could often still be legally supplied with heroin and use it. In 1924, the United States Congress passed additional legislation banning the sale, importation or manufacture of heroin in the United States. It is now a Schedule I substance, and is thus illegal in the United States.

Heroin was first synthesized in 1874 by C. R. Alder Wright, an English chemist working at St. Mary's Hospital Medical School in London, England.