Does Marijuana Act on the Brain for Weeks?
The active ingredient of marijuana is THC, which stands for Tetra-Hydro-Cannabinol. THC enters the bloodstream through the lungs if marijuana is smoked and then a small proportion (about 1%) then enters the brain. There are specific receptors in the brain for the THC, and the psychoactive effects are achieved within 10 to 30 minutes after smoking.