One kind of psycho-stimulant drug that can give negative effects on the body once dependence sets in is methamphetamine crystal. Crytal meth as it is often called is composed of chemicals such as n-methyl-1-phenyl-propan-2-amine. It is in crystal form, hence the name. It has an odorless and colorless characteristic. It can be of any size that that can look like a piece of rock. Methamphetamine crystal is a purer form of n-methyl-1-phenyl-propan-2-amine. This purer form produces more lasting and more intense effects on the body as compared to its other forms.