Delta 9 THC, also known as tetrahydrocannabinol, is the main psychoactive compound found in cannabis. It is responsible for the feeling of relaxation and euphoria that many people experience when consuming marijuana. Delta 9 THC is so relaxing because it interacts with the body's endocannabinoid system, specifically the CB1 receptors in the brain and central nervous system. These receptors play a key role in regulating mood, appetite, and pain sensation, and when THC binds to them, it can produce a sense of calm and well-being.