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Oxytocin

Studied for induction and augmentation of labour, prevention of postpartum haemorrhage and negative symptoms of schizophrenia, intranasal. A nine-residue hormone made in the hypothalamus, in obstetric use since the 1950s and FDA-approved as an injection for labour and postpartum bleeding.

categoryskin and other
clinical evidenceapproved
community adoptionmoderate
uses graded5
sources14
last reviewed24 Aug 2026
compound file

The answer, first. A nine-residue hormone made in the hypothalamus, in obstetric use since the 1950s and FDA-approved as an injection for labour and postpartum bleeding. The strongest evidence is for induction and augmentation of labour, graded A — approval or replicated trials. The approved indication.

Against expectant management, 8.4% versus 53.8% of women failed to deliver vaginally within 24 hours, RR 0.16, 95% CI 0.10 to 0.25, across 61 trials 2.

The rest of what it is sold for — core social symptoms of autism, intranasal, trust and prosocial behaviour, intranasal — grade D or E: a claim the human trials have already tested and not supported.

What it is used for

Every use graded on its own evidence, not the compound as a whole. 5 outcomes, ranked by what the human record supports.

#outcome · human · animal · gradewhat the best evidence actually shows
01Induction and augmentation of labour61 trials, 12,819 women · not the basisgrade AThe approved indication. Against expectant management, 8.4% versus 53.8% of women failed to deliver vaginally within 24 hours, RR 0.16, 95% CI 0.10 to 0.25, across 61 trials 2.
02Prevention of postpartum haemorrhage24 trials, 10,018 women · not the basisgrade AAlso on the label. Prophylactic oxytocin cut blood loss of 500 mL or more, RR 0.51, 95% CI 0.37 to 0.72 3. For 1000 mL or more, RR 0.59, 95% CI 0.42 to 0.83 3.
03Negative symptoms of schizophrenia, intranasal9 small RCTs, meta null · not the basisgrade CBlinded trials exist and disagree. A meta-analysis of 9 RCTs found no significant effect on negative symptoms 7. A 2026 meta-analysis found a small schizophrenia-subgroup effect, g = 0.12, 95% CI 0.01 to 0.23 6.
04Core social symptoms of autism, intranasal2 large RCTs, both null · prosocial rodent workgrade EThe trials have answered this. A 24-week trial in 290 children found no difference, least-squares mean difference -0.2, 95% CI -1.5 to 1.0, P = 0.61 4. A 106-patient trial agreed 5.
05Trust and prosocial behaviour, intranasal2 registered replications, both null · pair-bonding modelsgrade EA 2005 Nature experiment started this and the replications closed it. Two registered studies found no effect, and pooled equivalence testing across 532 participants placed any effect inside a minimal range 8910.
gradewhat it means
ARegulatory approval, or multiple adequately-powered trials agreeing with each other
BAt least one well-powered human randomised trial, with the direction replicated
CSmall or open-label human trials only
DAnimal or mechanism data only, with no controlled human outcome
EA claim the human trials have already killed

How it works

The proposed mechanism, in three steps. A mechanism is a reason to run a trial, never a substitute for one.

1targetBinds the oxytocin receptor, a class 1 G-protein-coupled receptor on myometrial smooth muscle whose density rises through pregnancy 13.
2signalReceptor activation raises intracellular calcium through inositol-trisphosphate store release, store-operated entry and voltage-operated entry 13.
3effectUterine contraction, the basis of both label indications 113. Intranasally, 24 IU raised cerebrospinal fluid oxytocin, peaking at 75 minutes 11.

What it does not do

Claims the current record does not support. Worth knowing before you set expectations.

not supported by the evidence

How it is used

What published protocols administered, and what the community reports doing. Descriptive on both counts, and never a recommendation.

routeIntravenous infusion or intramuscular injection on the label 1. The social-cognition literature and the research market use an intranasal spray.
formatSterile solution for injection, 10 USP units per mL, on the label 1.
published dosesLabel schedule, descriptive. Labour induction starts at 0.5 to 1 mU/min by infusion, rising 1 to 2 mU/min every 30 to 60 minutes. It rarely goes above 9 to 10 mU/min at term. Postpartum: 10 to 40 units in infusion, or 10 units intramuscularly after placental delivery 1. Intranasal social trials used 24 to 48 IU daily 4511.
human pharmacokineticsIntranasal 24 IU peaks in plasma at 15 minutes and falls by 75 minutes. Cerebrospinal fluid peaks later 11.
reported conventionsAs reported on peptide and biohacking forums, 2016 to 2026: intranasal sprays in the tens of international units. Taken before social occasions rather than daily. Sourced from compounders and research vendors. Convention, not guidance.
commonly paired withPT-141

This site does not publish protocols to follow. The doses above are what studies administered or what users report, stated as facts about the literature and the market. How protocols are structured, mixing and storage and the reconstitution calculator cover the arithmetic.

What to expect

Where a trial measured it, the trial. Where only the community reports it, that is said out loud.

onsetOn the label an infusion acts within minutes and is titrated every 30 to 60 minutes 1. Intranasally, plasma peaks at 15 minutes but cerebrospinal fluid takes 75, and the two do not correlate 11.
most common reportAs reported for the nasal route: mild warmth or ease in company, and often nothing distinguishable.
adverse effectsAcross 5 intranasal autism RCTs with 223 participants: nasal discomfort 14.3%, irritability 9.0%, tiredness 7.2%, diarrhoea 4.5%, none differing from placebo 12. The injectable label carries uterine rupture, arrhythmia and water intoxication 1.
the stop signalThe label's stop signal is uterine hyperstimulation or fetal distress, judged in hospital 1. As reported for nasal use: headache or a flat response ends a run.

Approval and status

What regulators and sport bodies have actually said, separately from what the evidence shows.

approvalFDA-approved as an injection for obstetric use. No approved intranasal product.
FDAApproved under the Pitocin label for labour and postpartum bleeding, by infusion or intramuscular injection only 1.
sport [WADA]Not named on the Prohibited List. It is an approved medicine.
sold asapproved medicine

Check the vial

The grade above describes a molecule studied under controlled conditions. It says nothing about the powder in a particular vial.

That gap is the one part of this market a reader can actually close. How to read a certificate of analysis covers the five measures in five minutes, and the 2026 audit grades vendors on the documents they publish against a rubric printed in full.

Questions we get

What is Oxytocin used for?

Its approved use is obstetric: starting or strengthening labour contractions, and controlling bleeding after delivery 1. Both hold at the top grade, with 61 trials in 12,819 women for induction and 24 trials in 10,018 women for haemorrhage 23.

Everything else, the intranasal use for trust, bonding and autism, is off-label and rests on a trial literature that has largely read null 469.

How is Oxytocin used?

Descriptively. The label gives it only by intravenous infusion or intramuscular injection. Induction starts at 0.5 to 1 mU/min and rises by 1 to 2 mU/min every 30 to 60 minutes. It rarely goes above 9 to 10 mU/min at term.

Postpartum control uses 10 to 40 units in infusion or 10 units intramuscularly 1. The social trials used 24 to 48 IU intranasally 45.

How long does Oxytocin take to work?

By infusion, within minutes, which is why the label titrates every 30 to 60 minutes 1. Intranasally the picture is stranger. Plasma oxytocin peaks at 15 minutes and falls by 75, while cerebrospinal fluid takes 75 minutes to rise.

The two do not correlate 11. Whatever reaches the brain does not track what a blood test would show.

Is Oxytocin an approved drug?

Yes, for a named indication in a named form. The approval covers an injectable product for obstetric use, not a nasal spray and not a research vial 1. That distinction carries most of the weight here.

The approved obstetric evidence is grade A. The intranasal social-cognition use that people actually buy it for has been tested repeatedly and largely read null 46910.

How do I know what is actually in a vial of Oxytocin?

You do not, unless a certificate of analysis for that specific lot says so. A certificate worth trusting covers five measures: identity, purity, measured net content, endotoxin and a microbial screen.

It names the lab that ran them and carries an accession number you can verify with that lab. Most certificates on this market cover one to three of the five. Purity alone is one number, not a quality programme.

References

  1. Pitocin, oxytocin injection USP, prescribing information. Par Pharmaceutical, via DailyMed, US National Library of Medicine. dailymed.nlm.nih.gov
  2. Alfirevic Z, Kelly AJ, Dowswell T. Intravenous oxytocin alone for cervical ripening and induction of labour. Cochrane Database Syst Rev. 2009. PMID 19821304
  3. Salati JA, Leathersich SJ, Williams MJ, et al. Prophylactic oxytocin for the third stage of labour to prevent postpartum haemorrhage. Cochrane Database Syst Rev. 2019. PMID 31032882
  4. Sikich L, Kolevzon A, King BH, et al. Intranasal Oxytocin in Children and Adolescents with Autism Spectrum Disorder. N Engl J Med. 2021. PMID 34644471
  5. Yamasue H, Okada T, Munesue T, et al. Effect of intranasal oxytocin on the core social symptoms of autism spectrum disorder: a randomized clinical trial. Mol Psychiatry. 2020. PMID 29955161
  6. Bonnieux J, Gumuchian ST, Harboun A, et al. Does intranasal oxytocin reduce symptoms of mental disorders? A meta-analysis of clinical trials. Neurosci Biobehav Rev. 2026. PMID 42134427
  7. Sabe M, Zhao N, Crippa A, et al. Intranasal Oxytocin for Negative Symptoms of Schizophrenia: Systematic Review, Meta-Analysis, and Dose-Response Meta-Analysis of Randomized Controlled Trials. Int J Neuropsychopharmacol. 2021. PMID 33890987
  8. Kosfeld M, Heinrichs M, Zak PJ, et al. Oxytocin increases trust in humans. Nature. 2005. PMID 15931222
  9. Declerck CH, Boone C, Pauwels L, et al. A registered replication study on oxytocin and trust. Nat Hum Behav. 2020. PMID 32514040
  10. Kroll CF, Schruers KRJ, Viechtbauer W, et al. Absence of a meaningful effect of intranasal oxytocin on trusting behavior: a registered report with pooled equivalence testing. Cortex. 2026. PMID 41880977
  11. Striepens N, Kendrick KM, Hanking V, et al. Elevated cerebrospinal fluid and blood concentrations of oxytocin following its intranasal administration in humans. Sci Rep. 2013. PMID 24310737
  12. Cai Q, Feng L, Yap KZ. Systematic review and meta-analysis of reported adverse events of long-term intranasal oxytocin treatment for autism spectrum disorder. Psychiatry Clin Neurosci. 2018. PMID 29232031
  13. Arrowsmith S, Wray S. Oxytocin: its mechanism of action and receptor signalling in the myometrium. J Neuroendocrinol. 2014. PMID 24888645
  14. Chen CY, Chiang YC, Kuo TC, et al. Effects of intranasal oxytocin in food intake and craving: A meta-analysis of clinical trials. Clin Nutr. 2021. PMID 34600216

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