• Testosterone (T): Sexual arousal from erotica or pornography rapidly boosts testosterone. In lab studies, men watching erotic films showed significant rises in T within minutes . For example, Hellhammer et al. found salivary T increased ~15 min after erotic stimulation . Similarly, Stoléru et al. observed a sharp LH pulse and higher serum T within 10 min of viewing a sexual film (25.2 vs 22.2 nmol/L in control) . These changes reflect hypothalamic GnRH and LH activation by erotic cues. (By contrast, neutral or aggressive films did not raise T .) Acute arousal thus triggers a transient T surge via increased LH pulsatility .
• Dopamine: Erotic stimuli powerfully engage the brain’s reward circuitry. Viewing novel sexual images floods dopamine in the mesolimbic pathway (ventral tegmental area to nucleus accumbens). Dopamine release in these circuits is essential for sexual motivation and erection . For instance, Giuliano and Allard note that dopamine in the nucleus accumbens and medial preoptic area “positively regulate” the anticipatory/motivational phase of copulation , and even trigger penile erection via hypothalamic oxytocinergic neurons . In practical terms, porn’s visual novelty generates strong dopamine surges that reinforce arousal and heighten desire (much as with other rewards).
• Cortisol: Contrary to stress, sexual arousal typically lowers the stress hormone cortisol. In erotic film studies, cortisol levels tend to decline or remain unchanged during arousal . For example, arousing stimuli have been reported to decrease cortisol even as they increase T . A review of lab studies concludes that sexual arousal (and orgasm) either does not change or actually suppresses cortisol . In other words, the parasympathetic-dominant arousal state blunts the HPA stress axis. (By contrast, stress or anxiety would raise cortisol and in turn suppress testosterone , but that normally does not occur in a comfortable sexual context.)
• Oxytocin and Prolactin (during arousal): Before orgasm, oxytocin and prolactin remain at baseline. (Oxytocin and prolactin are released at the moment of orgasm, see below.) In the pure arousal phase, their levels are generally unchanged – the dominant neurochemicals are dopamine and androgens rather than these “satiety” hormones.
Hormonal Changes at Orgasm
• Oxytocin: Oxytocin (“bonding hormone”) surges at ejaculation. Systematic reviews confirm that plasma oxytocin rises sharply with orgasm . Filippi et al. report that oxytocin is released from the pituitary at the moment of orgasm . This post-orgasm oxytocin may promote sperm transport in the ejaculatory ducts and also contributes to feelings of relaxation or bonding after climax.
• Prolactin (PRL): Prolactin spikes immediately after orgasm. Human studies show a surge of PRL around ejaculation . Traditionally, this PRL rise has been thought to help terminate sexual arousal (supporting the refractory period), although its exact role is debated. (Chronic hyperprolactinemia – e.g. from pituitary tumors or drugs – does suppress GnRH/LH and lower testosterone , but the acute post-orgasm PRL surge is more a short-term feedback.) In mice, blocking PRL did not abolish the refractory period , but in humans prolactin remains the best-known marker of orgasmic satiety.
• Testosterone and LH: Remarkably, a single orgasm does not elevate testosterone. Studies find that serum T is essentially unchanged by ejaculation . In Exton et al.’s experiment, plasma T before vs. after orgasm was the same, although a preceding period of abstinence raised the baseline T . (In other words, orgasm itself doesn’t boost T – rather, lack of orgasm for weeks can increase T.) Thus, the acute T rise occurs with arousal, not at climax.
• Cortisol: Similarly, cortisol is not elevated by orgasm. Just as in arousal, sexual climax tends to occur in a low-cortisol state. In fact, erotic stimulation tends to keep cortisol low . No major cortisol spike accompanies ejaculation in healthy men; if anything, cortisol generally remains flat or dips after orgasm in lab studies .
• Other: Orgasm also causes short-lived surges in catecholamines (adrenaline/noradrenaline) and endorphins, but these are secondary to the primary hormones above.
Chronic/Habitual Pornography Use
• Testosterone (baseline): Habitual porn use is linked to subtle endocrine adaptations. Anecdotally and in some studies, frequent sexual release is associated with a lower steady-state T than prolonged abstinence. For instance, one controlled study found that three weeks of sexual abstinence raised men’s baseline T, whereas orgasm itself had no effect . Thus, a man who ejaculates daily (via frequent porn viewing) may not experience the modest T boost seen with longer abstinence. On a population level, heavy porn use has been observationally correlated with altered sex-hormone profiles. A large Chinese cohort study reported that early and frequent pornography exposure was significantly associated with changes in gonadal steroids and poorer semen quality . (For example, they found that more frequent porn use – and attendant masturbation – correlated with lower estradiol and reduced sperm counts .) This suggests that chronic hyperstimulation of the HPG axis might subtly reset the endocrine balance, although causality is unclear.
• Dopamine (tolerance): The brain’s dopamine system adapts to chronic overuse of novel sexual cues. Repeated “supernormal” stimuli from internet porn flood dopamine release. Over time this causes neuroplastic changes and tolerance in the mesolimbic reward circuit . Doidge et al. summarize that compulsive, chronic porn viewing “stimulates neuroplastic changes” in the dopamine system, so that ordinary sexual stimuli become less rewarding . Functional imaging supports this: heavy users show reduced striatal response to brief sexual cues (consistent with downregulation) . In practice, this can mean desensitization: more extreme or novel content is needed to achieve the same arousal, and partnered sex may feel less stimulating.
• Prolactin & Oxytocin (chronic): Habitual usage per se doesn’t chronically elevate oxytocin or prolactin outside of orgasms. However, repeated high prolactin (from frequent ejaculations) would tend to suppress T and libido over time , similar to the effect of pituitary hyperprolactinemia. Any psychologic factors (guilt/anxiety) associated with porn use could raise stress and indirectly influence these hormones, but data are sparse.
• Cortisol (chronic): Chronic porn use might be a source of psychological stress for some, especially if it causes relationship issues or guilt. Chronic stress keeps cortisol elevated, which in turn can suppress testosterone and sexual desire. While acute sexual arousal normally lowers cortisol , habitual anxiety around one’s viewing habits could flip this. Importantly, studies of men show that acute cortisol spikes (from stress) reliably suppress testosterone . Thus, if a man experiences porn-related stress, his cortisol-T axis could shift downward over time.
• Summary: In sum, acute porn viewing triggers a hormonal cascade very similar to any erotic stimulus: dopamine surges drive arousal, T rises quickly, and both cortisol and LH follow expected patterns . Orgasm then produces a short-lived surge of prolactin and oxytocin, before the system resets. Habitual high-frequency porn use can lead to neuroendocrine adaptation (dampened dopamine response and blunted T baseline) and is correlated with changes in reproductive hormones and function . All these findings come from endocrine and neuroimaging studies in healthy men, and they underscore that pornography is a powerful sexual stimulus with clear short-term hormonal effects and plausible long-term neurohormonal consequences.
Sources: Peer-reviewed hormone and sexuality studies as cited above .