Oxytocin is mainly produced by the body in the following situations:
- social interaction
It is primarily produced in the hypothalamus of the brain. In pregnant women, it is also produced in the placenta. Synthetic oxytocin is bioidentical, but for obvious reasons not administered in the brain.
Synthesized oxytocin is mainly used to induce contractions in women. However, promising studies have been done on patients with schizophrenia:
The results revealed that intranasal oxytocin (40 international units twice a day), administered as an adjunct to subjects’ antipsychotic drugs for 3 weeks improved positive and negative symptoms significantly more than placebo
In other studies, the same treatment showed no effect:
Two small studies failed to detect any functional improvement from the use of intranasal oxytocin (multiple brands) in patients with schizophrenia, even when coupled with social skills training, research presented here indicates.
Other studies have been done in patients with autism:
Compared with placebo, oxytocin led to significant improvements on the primary outcome of caregiver-rated social responsiveness.
As of yet, oxytocin is only used for these conditions in studies. All of the studies so far have been done with small sample sizes.
So far, side effects of the nasal spray used in the schizophrenia and autism studies appear to be mild:
Overall, nasal spray was well tolerated, and the most common reported adverse events were thirst, urination and constipation
From another source:
The evidence shows that intranasal oxytocin: (1) produces no detectable subjective changes in recipients, (2) produces no reliable side-effects, and (3) is not associated with adverse outcomes when delivered in doses of 18–40 IU for short term use in controlled research settings. Future research directions should include a focus on the dosage and duration of use, and application with younger age groups, vulnerable populations, and with females.
As for the side effects of intravenously administered synthetic oxytocin during labor, there is a lot of information about it on the internet, and very few of it is sourced. Studies are hard to interpret because by design, the groups "no labor induction" and "labor induced" differ in more than the administration of oxytocin.
The Cochrane review on the topic concludes:
For women making slow progress in spontaneous labour, treatment with oxytocin as compared with no treatment or delayed oxytocin treatment did not result in any discernable difference in the number of caesarean sections performed. In addition there were no detectable adverse effects for mother or baby. The use of oxytocin was associated with a reduction in the time to delivery of approximately two hours which might be important to some women.
Synthesized oxytocin probably has no major side effects - however, it is not yet used regularly for any other medical reason than inducing labor.
Beyond Labor: The role of natural and synthetic oxytocin in the transition to motherhood
Oxytocin as a Potential Therapeutic Target for Schizophrenia and Other Neuropsychiatric Conditions
Oxytocin Shows No Effect in Schizophrenia
The effect of oxytocin nasal spray on social interaction deficits observed in young children with autism: a randomized clinical crossover trial
A review of safety, side-effects and subjective reactions to intranasal oxytocin in human research
Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour