Injecting Meth is a popular method for use, also known as slamming, but carries quite serious risks. The hydrochloride salt of methamphetamine is soluble in water; injection users may use any dose from 125 milligrams to over one gram using a hypodermic needle (Although it should be noted that typically street methamphetamine is "cut" with a water-soluble cutting material which constitutes a significant portion of that street meth dose).

Although the root causes of drug addiction remain unclear, the new study reveals that scientists have identified a number of biological, psychological and social conditions that can help to identify whether a person will become an addict.

The annual number of new cocaine users has generally increased over time. In 1975 there were 30,000 new users. The number increased from 300,000 in 1986 to 361,000 in 2000.

The kerosene is removed and gas crystals of crude cocaine are left at the bottom of the tank. Typically, the crystals are dissolved in methyl alcohol. They are then recrystallized and dissolved in sulfuric acid, which results in cocaine that is about 60% pure.