"The Hormone of Happiness"

Oxytocin has been called “The Love Hormone” and the “The Hormone of Happiness.”  These somewhat one-dimensional monikers belie a multi-dimensional collection of important actions that oxytocin exerts within human physiology. Oxytocin is a peptide hormone made of nine amino acids and is secreted by the posterior pituitary gland in the brain.  Oxytocin plays a well-known role in pregnancy-related uterine contractions and lactation.  Recent research has brought to light a new understanding of oxytocin actions in many other body systems.

Oxytocin and Pain

Oxytocin plays an intriguing role in pain perception and pain physiology.  Oxytocin receptors participate in modulating visceral pain, which perhaps is not a surprise given oxytocin’s involvement in childbirth. One novel application for oxytocin is for the treatment of migraine and acute headache. A recently published double-blind, placebo controlled study showed a strong dose-response effect with intranasal oxytocin and headache pain. (Fig. 1)

Oxytocin and Sexual Physiology

Male erectile tissues are one of the main peripheral target areas for oxytocin.  Oxytocin joins nitric oxide, dopamine, vasopressin and other signaling molecules such as cyclic guanosine monophosphate (cGMP) to regulate erectile function. Oxytocin is an emerging agent in the treatment of erectile dysfunction and male anorgasmia, with recent successful case reports published for both conditions.

In women, oxytocin levels are higher after orgasm compared to baseline levels.[xv]  However, oxytocin appears to play a more complex role in the sexual experience in women compared to men.  Oxytocin strengthens attachment, affection and trust between partners, fostering increased intimacy and emotional connection.

Oxytocin and Stress

Oxytocin exerts anxiolytic and stress attenuating effects. There appear to be multiple mechanisms of action including an inhibitory influence on the amygdala.

Lactating women had reduced plasma ACTH, cortisol and glucose responses in comparison to postpartum non-lactating women. A 2003 study demonstrated that supplemental oxytocin in the form of a nasal spray decreased the stress response to a psychological stressor.  This study, a double blind placebo controlled trial, subjected men to a stressful public speaking event in a controlled setting.  Supplemental oxytocin together with social support before the stressful event significantly reduced cortisol and increased calmness. (Fig. 2)

Several Studies have examined oxytocin's role as a treatment and prevention strategy in Post-Traumatic Stress Disorder (PTSD).

Oxytocin replacement appears to have interesting potential as a therapeutic stress response attenuator.

Who Should be Tested?

Published research suggests that oxytocin may benefit people with the following conditions:

  • Autism
  • Depression
  • Sexual dysfunction, especially erectile dysfunction
  • Headache, fibromyalgia and chronic pain syndromes
  • Maladaptive stress syndromes
  • Cases of extreme social avoidance/ social withdrawal
  • Patients seeking weight loss
  • Osteopenia
  • Low muscle mass

Figure 1


Figure 2