Oxytocin is a hormone and neurotransmitter produced by the hypothalamus and released by the pituitary gland. Often referred to as the “love hormone” or “bonding hormone,” oxytocin plays a crucial role in social bonding, maternal-infant attachment, and the regulation of social and emotional behaviors. It is released in response to various stimuli, including physical touch, childbirth, and social interactions, promoting feelings of trust, intimacy, and connection.
Binds to receptors in the brain and stimulates endogenous opioid release
Lowers serum cortisol improving mood and decreasing stress
Promotes feelings of intimacy (during climax, levels increase five-fold)
Causes vasodilation and increased blood flow to the genitals and NF-kB.
Metabolism
Rapidly metabolized by the liver and in plasma by oxytocinases (very short half-life of 1 to 6 minutes)
Poor oral bioavailability due to quick degradation in the GI tract
Stability
68 – 77⁰F for solid dosage forms
Refrigerate solutions
Routes available
Sublingual (SL)
Intranasal (IN)- reliable peak (30 minutes) and decrease (150 minutes)
Vaginally
Not available orally (GI degradation)
Bioavailability variability is seen in SL, vaginal, and IN dosage forms, both inter- and intra-individually with an average bioavailability of 2.5%
The most common side effects are reported with traditional, IV or IM formulations.
Intranasal- runny or stuffy nose, watery eyes, headaches, behavioral changes, feeling relaxed, light headed, anxious, and “fuzzy”
Sublingual and vaginal- no reported side effects
Male Sexual Dysfunction– Oxytocinergic neurons (play an important role in erectile function) are activated by endogenous substances (dopamine, excitatory amino acids, and oxytocin) while antagonists will cause sexually potent males to lose erections.
Improvement in spontaneity, non-sexual closeness, arousability, and ejaculation time is seen while using 24 IU daily of oxytocin intranasally.
Female Sexual Dysfunction- Beneficial for both arousal and orgasmic disorders. Orgasmic women have higher levels of endogenous oxytocin, which peaks during orgasm. Women applying 32 IU of oxytocin intranasally up to 50 minutes before intercourse was shown to improve sexual function index score from base line.
Vaginal Atrophy– Oxytocin 500 IU/mL vaginal gel, applying 1 mL intravaginally every day for 7 days showed significant improvement including vaginal mucosa improvement, symptomatic relief, and histological changes. 100 IU daily for 7 weeks significantly improved the condition of vaginal mucosa and decreased pH. 400 IU daily for 7 weeks significantly reduced the most bothersome symptoms. Most common side effects seen in local estrogen treatments, such as growth of the endometrium were absent. Side effects from oxytocin are minimal when applied vaginally, and the vaginal dosage form could be considered as an alternate for local estrogen treatment.
Pain– The unique combination of SL oxytocin and SL ketamine displayed the ability to relieve intractable pain in patients previously on opioids with little to no relief. The relief was documented to last for 4 hours with no additional side effects.
Migraines– Intranasal treatment has shown improvements in patients within 2-4 hours, if active migraine for at least 10 hours and history of at least 15 migraine days per month. However, taking an NSAID before receiving oxytocin, lessened the effect compared to patients that did not take an NSAID.
Anxiety– Oxytocin represses fear responses by inhibiting the amygdala. Males with social-anxiety showed that doses of oxytocin promote pro-social behavior and help with anxiety in romantic relationships. Oxytocin is known to improve processing of positive social queues. A study of males suffering from social anxiety was performed on patients in weekly therapy sessions. The patients were given 24 IU of intranasal oxytocin or placebo prior to each session. The oxytocin patients rated their appearance and performance higher when speaking to the group than those receiving placebo.
Autism– Adult males with Autism Spectrum Disorder (ASD), received 24IU of oxytocin twice daily intranasally. Long term administration of oxytocin improved the Autism Diagnostic Observation Scale scores as well as an increase in eye fixation time and non-verbal judgements.
In children, studies focused on the improvement of social deficits between children with ASD and their unaffected counterparts. 12 IU given twice daily for 5 weeks caused a significant improvement in the social functioning of children between 3 and 8 years old. Children 6 to 12 years old receiving 24 IU twice daily for 4 weeks showed similar results.
Breastfeeding– Intranasal treatment may be useful as a temporary treatment for 2-3 days post-partum. To be given at a dose of 40 IU/mL intranasal, give 1 spray into one or both nostrils 2-3 minutes prior to pumping for 10 minutes, four times daily.
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