What are the neurohormonal changes in men and women after sex?

Neurohormonal Changes After Sexual Activity

The most consistent and pronounced neurohormonal change following orgasm in both men and women is a sustained elevation in prolactin levels, which increases immediately after orgasm and remains elevated for an extended period, serving as the most reliable biological marker of orgasm and sexual satiety. 1, 2

Prolactin Response

Prolactin represents the most robust and sustained hormonal change following sexual activity:

• Prolactin levels increase immediately after orgasm in both sexes and remain elevated throughout the post-orgasmic period (at least 40 minutes), making it a more reliable marker than oxytocin 1
• The magnitude of prolactin increase is 400% greater following penile-vaginal intercourse compared to masturbation in both men and women, suggesting intercourse produces greater physiological satiety 2
• In women, post-orgasmic prolactin surges correlate strongly with orgasm quality (r = 0.85) and sexual satisfaction (r = 0.75), providing an objective neurohormonal index of sexual experience quality 3
• Prolactin likely functions as a feedback mechanism modulating central dopaminergic systems responsible for sexual appetite and arousal, effectively signaling sexual satiety 1, 2

Catecholamine Response

Sympathoadrenal activation occurs transiently during orgasm:

• Plasma epinephrine and norepinephrine levels increase acutely during orgasm in men, with rapid decline immediately thereafter 1
• This transient sympathetic surge reflects the acute autonomic activation associated with the orgasmic phase 1

Oxytocin Response

Oxytocin shows variable and less consistent changes:

• Plasma oxytocin levels increase during sexual arousal in both sexes and are significantly higher during orgasm/ejaculation compared to baseline 4
• However, oxytocin changes are not consistent across individuals and do not reach statistical significance in all studies, making it a less reliable marker than prolactin 1
• When present, oxytocin elevation correlates with smooth muscle contractions of the reproductive system during orgasm 4
• Oxytocin levels correlate positively with systolic blood pressure, electromyographic intensity, and anal photoplethysmography during sexual response 5

Hormones That Do NOT Change

Several reproductive hormones remain unaltered during sexual activity:

• Testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and vasopressin plasma concentrations show no significant changes during sexual arousal or orgasm in men 1
• This finding contradicts common misconceptions about testosterone fluctuations during sexual activity 1

Sex Differences in Hormonal Response

While the pattern of prolactin and oxytocin response is similar between sexes, magnitude and correlations differ:

• Both men and women show prolactin increases after orgasm, but the correlation with subjective orgasm intensity is significant only in multiorgasmic women 5
• The 400% greater prolactin response to intercourse versus masturbation occurs in both sexes, suggesting similar neurohormonal mechanisms of sexual satiety 2

Clinical Implications

Understanding these neurohormonal patterns has practical applications:

• Post-orgasmic prolactin elevation explains the refractory period and decreased sexual interest following orgasm 1, 2
• The greater prolactin response to intercourse versus masturbation provides biological evidence for differential physiological satisfaction between sexual activities 2
• Prolactin measurement could potentially serve as an objective biomarker in research on sexual dysfunction or treatment efficacy 3

Important Caveats

• The evidence base consists primarily of laboratory studies with small sample sizes (9-13 subjects), limiting generalizability 1, 4, 5, 3
• Individual variability exists, particularly for oxytocin responses 1
• Most studies focus on orgasm achieved through self-stimulation or intercourse; data on other sexual activities are limited 2