THC

Tetrahydrocannabinol

THC has mild to moderate analgesic effects, and medical cannabis can be used to treat pain. The mechanism for analgesic effects caused directly by THC or other cannabinoid agonists is not fully elucidated. Other effects include relaxation; euphoria; altered space-time perception; alteration of visual, auditory, and olfactory senses; disorientation; fatigue; and appetite stimulation. The mechanism for appetite stimulation in subjects is believed to result from activity in the gastro-hypothalamic axis. CB1 activity in the hunger centers in the hypothalamus increases the palatability of food when levels of a hunger hormone, ghrelin, increase as food enters the stomach. After chyme is passed into the duodenum, signaling hormones such as cholecystokinin and leptin are released, causing reduction in gastric emptying and transmission of satiety signals to the hypothalamus, respectively. Cannabinoid activity is reduced through the satiety signals induced by leptin release. It also has anti-emetic properties, and also may reduce aggression in certain subjects.
THC has an active metabolite, 11-Hydroxy-THC, which may also play a role in the analgesic and recreational effects of the herb.