Even though scientists are not clear on the matter, we know that cannabis does affect the endocrine system. What scientists do know, is that CBD tends to monopolize certain metabolic enzymes. The metabolic enzymes are found in the liver where they are responsible to transform digested compounds into biological useful ones. A group of enzymes, called cytochrome P450, is influenced by CBD. It inhibits the activity of CYP2C9, CYP2C19, and CYP3A4.