Delta-9 THC is the psychotropic compound that gives marijuana its "high" effect. Delta-9 THC binds to the CB1 receptors in the endocannabinoid system.The "high" effect of marijuana is a result of THC binding to the brain's CB1 receptors, creating a sense of pleasure and bliss. Interestingly, the "runner's high" essentially does the same thing - positively stimulating the CB1 receptors in the body's endocannabinoid system.