Cannabinoids are a group of chemical compounds that can stimulate cannabinoid receptors on cells that repress neurotransmitter releases in the human brain. Receptor proteins include the endocannabinoids which are naturally produced within humans and animals), the phytocannabinoids (often found in cannabis but also in other plants) and synthetic-cannabinoids (which are produced artificially by humans). thc is the most prominent cannabinoid, which is the primary psychoactive compound within marijuana. There are at least 85 isolated cannabinoids isolated that can be harvested from cannabis.