Oxytocin
Also known as: Pitocin, Syntocinon, OXT
Oxytocin (also called Pitocin or Syntocinon) is an FDA-approved nonapeptide hormone in the Oxytocin receptor agonist class. Oxytocin is a nonapeptide synthesised in the hypothalamic paraventricular and supraoptic nuclei and released from the posterior pituitary. It acts at the oxytocin receptor, a Gq-coupled receptor that raises intracellular calcium.
For research use only.
Key Facts
- CAS
- 50-56-6
- Molecular Weight (MW)
- 1007.2 g/mol
- Half-life
- 1–6 minutes (IV)
- FDA status
- Approved
- Administration Route
- Intravenous / Intramuscular
- Frequency
- Continuous IV in labor; IM postpartum as labeled
- Last updated
- Aug 30, 2026
- Reviewed
- Aug 30, 2026
- Targets
- OXTR
Vendor price snapshot
Price per mg is list price divided by vial size in milligrams when both are known from public vendor listings. Peptide Library does not sell peptides. Confirm live prices on the vendor site.
- Vendors listing this peptide
- 3
- Listed offers
- 3
- Price per mg range
- $6.50–$12.50/mg
Research summary
FDA-approved nonapeptide (Pitocin) for labor induction/augmentation and postpartum hemorrhage. Intranasal research use for social cognition is not an approved indication.
Peptide Library's Oxytocin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- Obstetric IV infusion per label (milliunits/min)
- Frequency
- Continuous IV in labor; IM postpartum as labeled
- Cycle
- Peripartum only as labeled
- Administration Route
- Intravenous / Intramuscular
- Reconstitution Guide
- —
- Timing Notes
- Educational catalog only — not medical advice
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. Oxytocin is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C43H66N12O12S2 |
|---|---|
| Molecular weight | 1007.2 g/mol |
| CAS number | 50-56-6 |
| Half-life | 1–6 minutes (IV) |
| Appearance | Solution for injection |
| Formulation | Solution |
| PubChem CID | 439302 |
| FDA UNII | 1JQS135EYN |
| ChEMBL | CHEMBL395429 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Oxytocin is a nonapeptide synthesised in the hypothalamic paraventricular and supraoptic nuclei and released from the posterior pituitary. It acts at the oxytocin receptor, a Gq-coupled receptor that raises intracellular calcium. Peripherally this produces rhythmic contraction of uterine myometrium — with receptor density rising sharply near term, which is why sensitivity is gestation-dependent — and contraction of mammary myoepithelial cells for milk ejection. Centrally, oxytocin released within the brain acts as a neuromodulator in circuits governing social recognition, pair bonding and stress reactivity. Peripheral administration crosses the blood-brain barrier poorly, which is why intranasal routes are used in behavioural research and why peripheral and central effects should not be assumed equivalent.
Origin
Endogenous cyclic nonapeptide; synthetic pharmaceutical.
Targets
Studies
- Oxytocin and postpartum depression: A systematic review
- Association of postpartum oxytocin dose and postpartum bleeding outcomes in nulliparous patients at term
- The effects of intranasal oxytocin on the efficacy of psychotherapy for major depressive disorder: a pilot randomized controlled trial
- The Role of Oxytocin in Parental Care
- The physiology and pharmacology of oxytocin in labor and in the peripartum period
Regulatory & research status
Oxytocin is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.
| FDA status | Approved |
|---|---|
| Availability | Prescription-Only |
| WADA (sport) | Permitted |
| Library classification | FDA-Approved |
Benefits
Potential Side Effects
Side Effects
- Water intoxication
- Uterine hyperstimulation
- Hypotension
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Oxytocin: frequently asked questions
What is Oxytocin?
FDA-approved nonapeptide (Pitocin) for labor induction/augmentation and postpartum hemorrhage. Intranasal research use for social cognition is not an approved indication.
How does Oxytocin work?
Oxytocin is a nonapeptide synthesised in the hypothalamic paraventricular and supraoptic nuclei and released from the posterior pituitary. It acts at the oxytocin receptor, a Gq-coupled receptor that raises intracellular calcium.
Is Oxytocin FDA approved?
Yes. Oxytocin is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.
What is the half-life of Oxytocin?
Reported half-life for Oxytocin is 1–6 minutes (IV). Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
Is Oxytocin banned in sport?
Oxytocin is recorded here as permitted in sport. Anti-doping status is revised annually, so athletes subject to testing should confirm against the current WADA Prohibited List before use.
What peptides are similar to Oxytocin?
Compounds most often compared with Oxytocin include Carbetocin, Atosiban, Bremelanotide and Gonadorelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- Pitocin labelExternal reference
- Oxytocin and postpartum depression: A systematic review — Psychoneuroendocrinology, 2020External reference
- Association of postpartum oxytocin dose and postpartum bleeding outcomes in nulliparous patients at term — Am J Obstet Gynecol, 2025External reference
- The effects of intranasal oxytocin on the efficacy of psychotherapy for major depressive disorder: a pilot randomized controlled trial — Psychol Med, 2024External reference
- The Role of Oxytocin in Parental Care — Endocrinology, 2025External reference
- The physiology and pharmacology of oxytocin in labor and in the peripartum period — Am J Obstet Gynecol, 2024External reference
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Aug 30, 2026 · Version 1
This Oxytocin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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