Addyi is not a hormone or a hormonal treatment. Addyi is a centrally acting multifunctional serotonergic agonist and antagonist. Based on findings from preclinical studies, it is thought that Addyi transiently decreases serotonin activity and increases dopamine and norepinephrine activity to restore an appropriate balance of excitatory and inhibitory activity of the brain reward centers to the prefrontal cortex. The precise mechanism of action by which Addyi enhances sexual desire in women with hypoactive sexual desire remains unknown.24