Acomplia Ireland UK France Italy Europe patient - Rimonabant works by blocking receptors called cannabinoid-1 receptors (CB1). These are found in the brain, fat tissue, digestive system, liver and muscles. The CB1 receptors are part of a system in the body called the endocannabinoid system. This system has only recently been discovered and explored. It is involved in regulating energy balance, sugar and fat metabolism and body weight.