Increases in libido and feelings of well-being are often mediated by dopamine and serotonin activation, influenced by hormones like testosterone and estrogen.

“Well, many of those effects we know are not due to direct effects of testosterone and estrogen, but rather are due to the effects of testosterone and estrogen on the neuromodulators, dopamine and serotonin, because much of libido and feelings of well-being and feelings of relaxation, but also desire, motivation, et cetera, originate because of the activation of neural circuits that dopamine controls and promotes and that serotonin promote and control.”