Oxytocin
Nine-amino-acid posterior pituitary hormone; synthetic oxytocin injection (Pitocin) is FDA-approved for medically indicated induction or stimulation of labour and postpartum use, given in hospital.
60-Second Scientific Briefing
Oxytocin is a natural nine-amino-acid hormone from the posterior pituitary that causes uterine contractions and milk let-down. Synthetic oxytocin injection (Pitocin) is FDA-approved for medically indicated induction or stimulation of labour and to control bleeding after delivery, given by intravenous infusion under hospital supervision. Uses for social behaviour, anxiety or weight are not approved, and large randomised trials of nasal oxytocin in autism (NEJM 2021) and obesity (NEJM Evidence 2024) showed no benefit over placebo.
What is Oxytocin?
Pharmacological Classification & Molecular IdentityOxytocin is a nine-amino-acid peptide hormone (nonapeptide) of the posterior pituitary. The medicine is prepared synthetically to avoid contamination with vasopressin and other pituitary peptides. [1] U.S. National Library of Medicine (DailyMed), 2026 ↗
Verified Chemical & Regulatory Registry Identifiers
Mechanism of Action & Receptor Targets
Biological Pathway and Target BindingReceptor Selectivity: Acts on oxytocin receptors in the uterine muscle, whose number rises sharply in pregnancy, and promotes contractions by increasing intracellular calcium. Because its structure differs from vasopressin by two amino acids, large doses have antidiuretic (water-retaining) and pressor effects. Plasma half-life is about 1 to 6 minutes (prescribing information). [1] U.S. National Library of Medicine (DailyMed), 2026 ↗
Regulatory & FDA Approval Status
Legal and Regulatory ClassificationsSynthetic oxytocin injection (Pitocin) is FDA-approved for medically indicated induction of labour, stimulation of labour in selected cases, adjunctive management of incomplete or inevitable abortion, and after delivery to produce uterine contractions and control postpartum bleeding. The label states it is not indicated for elective induction of labour. Nasal or other uses for social behaviour, anxiety or weight are not approved. [1] U.S. National Library of Medicine (DailyMed), 2026 ↗
Synthetic oxytocin injection (Pitocin) is FDA-approved for medically indicated induction of labour, stimulation of labour in selected cases, adjunctive management of incomplete or inevitable abortion, and after delivery to produce uterine contractions and control postpartum bleeding. The label states it is not indicated for elective induction of labour. Nasal or other uses for social behaviour, anxiety or weight are not approved.
Human Evidence & Clinical Trials
Clinical Study Readouts and Evidence SynthesesThe approved obstetric uses rest on long clinical experience described in the label. Outside obstetrics: in a 24-week phase 2 trial of nasal oxytocin in 290 children and adolescents with autism (NEJM 2021) social withdrawal scores did not differ from placebo (difference −0.2; P=0.61); in an 8-week randomised trial in 61 adults with obesity (NEJM Evidence 2024) nasal oxytocin four times daily did not reduce body weight (0.20 vs 0.26 kg; P=0.934). [1] NEJM Evidence, 2024 ↗ [2] N Engl J Med, 2021 ↗
Clinical Evidence
The approved obstetric uses rest on long clinical experience described in the label. Outside obstetrics: in a 24-week phase 2 trial of nasal oxytocin in 290 children and adolescents with autism (NEJM 2021) social withdrawal scores did not differ from placebo (difference −0.2; P=0.61); in an 8-week randomised trial in 61 adults with obesity (NEJM Evidence 2024) nasal oxytocin four times daily did not reduce body weight (0.20 vs 0.26 kg; P=0.934).
Safety Profile & Clinical Limitations
Documented Adverse Events and Known UncertaintiesThe label lists uterine hyperstimulation, uterine rupture, postpartum haemorrhage, cardiac arrhythmias, hypertensive episodes, subarachnoid haemorrhage, anaphylaxis, nausea and vomiting in the mother, and fetal bradycardia, arrhythmias and neonatal jaundice. Its antidiuretic effect can cause water intoxication with seizures and coma; maternal deaths from water intoxication have been reported. In labour it must be given only intravenously under continuous medical supervision in hospital. [1] U.S. National Library of Medicine (DailyMed), 2026 ↗
There is no established benefit of nasal oxytocin for social, psychiatric or weight indications; the largest randomised trials in autism and obesity were negative. Products sold outside regulated pharmacies have unknown content. [1] NEJM Evidence, 2024 ↗ [2] N Engl J Med, 2021 ↗
Dose Approval Status
Commercial Dosing Status and Policy DirectivesApproved US labelling: for induction or stimulation of labour, intravenous infusion is the only acceptable route; the dose is individualised to the uterine response, started at a very low level and given with accurate rate control and continuous monitoring in hospital. Postpartum use follows the label. Dosing is set by the obstetric team. [1] U.S. National Library of Medicine (DailyMed), 2026 ↗
Under Egypt Peptides medical governance policies, no personal dosages, titration intervals, cycles, stacking recommendations, or self-injection instructions may be provided for unapproved investigational compounds. Clinical study protocols represent controlled experimental research parameters exclusively.
What is Known vs. What is Unknown
Evidence Comparison and Clinical Evidence Boundaries✓ Confirmed Scientific Evidence
- Oxytocin is a nine-amino-acid peptide hormone (nonapeptide) of the posterior pituitary. The medicine is prepared synthetically to avoid contamination with vasopressin and other pituitary peptides.
- Targets & Selectivity: Acts on oxytocin receptors in the uterine muscle, whose number rises sharply in pregnancy, and promotes contractions by increasing intracellular calcium. Because its structure differs from vasopressin by two amino acids, large doses have antidiuretic (water-retaining) and pressor effects. Plasma half-life is about 1 to 6 minutes (prescribing information).
- The approved obstetric uses rest on long clinical experience described in the label. Outside obstetrics: in a 24-week phase 2 trial of nasal oxytocin in 290 children and adolescents with autism (NEJM 2021) social withdrawal scores did not differ from placebo (difference −0.2; P=0.61); in an 8-week randomised trial in 61 adults with obesity (NEJM Evidence 2024) nasal oxytocin four times daily did not reduce body weight (0.20 vs 0.26 kg; P=0.934).
- Safety considerations: The label lists uterine hyperstimulation, uterine rupture, postpartum haemorrhage, cardiac arrhythmias, hypertensive episodes, subarachnoid haemorrhage, anaphylaxis, nausea and vomiting in the mother, and fetal bradycardia, arrhythmias and neonatal jaundice. Its antidiuretic effect can cause water intoxication with seizures and coma; maternal deaths from water intoxication have been reported. In labour it must be given only intravenously under continuous medical supervision in hospital.
? Unknown / Under Ongoing Investigation
- There is no established benefit of nasal oxytocin for social, psychiatric or weight indications; the largest randomised trials in autism and obesity were negative. Products sold outside regulated pharmacies have unknown content.
Verified Questions & Answers
10 Verified scientific answers with permanent anchor keysOxytocin is a natural nine-amino-acid hormone from the posterior pituitary that causes uterine contractions and milk let-down. Synthetic oxytocin (Pitocin) is an approved hospital medicine for labour and after delivery.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
It acts on oxytocin receptors in the uterus, which increase sharply in pregnancy, and triggers contractions by raising calcium inside muscle cells. At large doses it also retains water like vasopressin.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
Yes, for specific obstetric uses. Pitocin is FDA-approved for medically indicated induction or stimulation of labour and to control bleeding after delivery; it is not indicated for elective induction. Uses for social behaviour, anxiety or weight are not approved.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
The obstetric uses are established in the label. Nasal oxytocin failed in two large randomised trials: autism in 290 children (NEJM 2021, no difference from placebo) and obesity in 61 adults (NEJM Evidence 2024, no weight loss).
Autism (NEJM 2021): a 24-week, placebo-controlled phase 2 trial in 290 children and adolescents aged 3 to 17 given nasal oxytocin daily; the change in the Aberrant Behavior Checklist social-withdrawal score was −3.7 vs −3.5 with placebo (difference −0.2; P=0.61), secondary outcomes did not differ, and adverse events were similar. Obesity (NEJM Evidence 2024): 61 adults with obesity received nasal oxytocin or placebo four times daily for 8 weeks; weight change was 0.20 vs 0.26 kg (P=0.934), with no benefit on body fat, visceral fat, liver fat or energy expenditure.
- Intranasal Oxytocin for Obesity (NEJM Evidence, 2024-05-01)
- Intranasal Oxytocin in Children and Adolescents with Autism Spectrum Disorder (N Engl J Med, 2021-10-14)
The label warns of uterine hyperstimulation and rupture, bleeding, heart-rhythm problems, high blood pressure, allergic reactions, and water intoxication with seizures and coma, which has caused maternal deaths. In labour it is given only by intravenous infusion with continuous monitoring in hospital.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
No benefit of nasal oxytocin has been established for social, psychiatric or weight indications; the largest trials were negative. Products sold outside regulated pharmacies have unknown content.
- Intranasal Oxytocin for Obesity (NEJM Evidence, 2024-05-01)
- Intranasal Oxytocin in Children and Adolescents with Autism Spectrum Disorder (N Engl J Med, 2021-10-14)
Approved US labelling: for labour, intravenous infusion only, individualised to the uterine response, started very low with accurate rate control and continuous monitoring in hospital. Dosing is set by the obstetric team.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
Per the Pitocin prescribing information: store at 20–25 °C.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
Oxytocin is not named on the 2026 WADA Prohibited List. Athletes should confirm with their national anti-doping organisation.
- WADA Prohibited List (World Anti-Doping Agency)
Egypt Peptides publishes reviewed scientific reference monographs for documentation and research. The site does not give individual medical advice, preparation or injection instructions, combination protocols or off-label use instructions. Decisions about any medicine belong to the treating physician.
- Pitocin (oxytocin injection, USP): prescribing information (U.S. National Library of Medicine (DailyMed), 2026-05-21)
Authoritative Sources & Literature Registry
Regulatory dossiers, clinical trial registries, and published studiesPitocin (oxytocin injection, USP): prescribing information ↗
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6e5a66fc-e507-497c-b5ce-44a8c95898ad
Intranasal Oxytocin for Obesity ↗
https://pubmed.ncbi.nlm.nih.gov/38815173/
Intranasal Oxytocin in Children and Adolescents with Autism Spectrum Disorder ↗
https://pubmed.ncbi.nlm.nih.gov/34644471/