The half-life of marijuana is roughly 30-60 days. Meaning, you'll feel the effects for about 30-45 minutes, but it metabolizes over a period of 1-2months. [b]Cocaine[/b] leaves your body within a period of 2 days, whereas alcohol within a period of a few hours. I'll assume you advocate [b]meth[/b], since you're judging by the amount of time required to leave the body.