Humans appear to have built-in mechanisms that encourage a period of recovery after sexual satiety. Interestingly, animal studies reveal that androgen receptors (which respond to testosterone) temporarily decline with each ejaculation, suppressing libido for some period of time.

Human

[Periodic changes in serum testosterone levels after ejaculation in men]

Orgasmic frequency and plasma testosterone levels in normal human males

Endocrine response to masturbation-induced orgasm in healthy men following a 3-week sexual abstinence

Androgen Regulation of the Mesocorticolimbic System and Executive Function

Animal

Anabolic androgens restore mating after sexual satiety in male rats

Changes in the sexual behavior and testosterone levels of male rats in response to daily interactions with estrus females

Effects of testosterone metabolites on copulation and medial preoptic dopamine release in castrated male rats

Hormonal responses to different sexually related conditions in male rats

Relationship Between Sexual Satiety and Brain Androgen Receptors

Relationship between sexual satiety and motivation, brain androgen receptors and testosterone in male mandarin voles

Sexual Behavior Reduces Hypothalamic Androgen Receptor Immunoreactivity

Testosterone restoration of copulatory behavior correlates with medial preoptic dopamine release in castrated male rats