Compounds / Oxytocin

Oxytocin

Also known as: Oxytocin; Pitocin; syntocinon; alpha-hypophamine; CAS 50-56-6

FDA APPROVED Tier 1 – Approved Hormonal and ReproductiveNeurological

Primary research focus: Obstetric use (labor induction and augmentation, postpartum hemorrhage control); intranasal use for social and behavioral research is off-label

Last updated July 2026 · Reviewed against FDA labeling and published research.

What is Oxytocin?

Oxytocin is a naturally occurring nonapeptide hormone produced in the hypothalamus and released by the posterior pituitary, with roles in uterine contraction, milk let-down, and social bonding. As a medicine it is FDA-approved only as an injectable (Pitocin and generic oxytocin injection USP) for specific obstetric indications. The intranasal and sublingual forms popularly associated with bonding, mood, and social effects are compounded preparations that are not FDA-approved for any indication.

How it works

Oxytocin binds the oxytocin receptor, a Gq-coupled G protein-coupled receptor. In uterine smooth muscle it raises intracellular calcium and increases the frequency and force of contractions, with receptor density rising markedly near term, which is why responsiveness is gestation-dependent. In the breast it contracts myoepithelial cells to produce milk ejection. Centrally, oxytocin released within the brain modulates amygdala reactivity, social salience, trust, and stress responses, which is the basis for the research interest in intranasal delivery. A crucial pharmacological point: peripherally administered oxytocin crosses the blood-brain barrier poorly, so subcutaneous or intravenous dosing raises plasma levels without reliably producing central effects. Oxytocin also has structural similarity to vasopressin and mild antidiuretic activity, which underlies the water-intoxication risk at high doses.

How it’s supplied

Brand / trade names: Pitocin

Supplied as FDA-approved oxytocin injection USP (for example, Pitocin) in vials for intravenous infusion or intramuscular injection, used in obstetric settings. Compounded intranasal sprays, sublingual troches, and injections are prepared by 503A pharmacies under prescription; these are not FDA-approved, and concentration, excipients, and quality vary by pharmacy. Products sold over the counter as oxytocin sprays or supplements are not legitimate pharmaceutical oxytocin.

Dosage Chart

RouteSubcutaneous
For reference only, compiled from FDA labeling, clinical trials, and established protocols. Not medical advice or a dosing recommendation. Confirm against current prescribing information and consult a qualified healthcare professional.
Vial size
BAC water

Units shown are for a U-100 insulin syringe (100 units = 1 mL), calculated from the vial size and BAC water you select. Always confirm against your prescription and your syringe markings.

PhaseDoseFrequencyNotes
Weeks 1-2 100mcg 1x Daily
Weeks 3-4 200mcg 1x Daily
Weeks 5-6 300mcg 1x Daily
Weeks 7-8 400mcg 1x Daily
Weeks 9-12 500mcg 1x Daily
Special considerations
  • Rotate injection sites to reduce irritation and lipohypertrophy
  • Not for use during pregnancy or breastfeeding
  • Do not exceed the recommended dose to try to speed results

Potential Benefits and Side Effects

Effects reported in published research. Not a promise of results, and not medical advice.

Reported benefits
  • Established for the approved obstetric indications; behavioral and social uses are off-label and not established.
  • Induces and augments labor when medically indicated.
  • Controls postpartum uterine bleeding by producing sustained uterine contraction.
  • Supports milk let-down.
  • Studied in research for effects on social cognition, trust, anxiety, and bonding via intranasal delivery (results mixed; no approved indication).
Reported side effects
  • Obstetric (per the approved labeling): uterine hyperstimulation and tetanic contractions, uterine rupture, postpartum hemorrhage, cardiac arrhythmias, nausea and vomiting, and severe water intoxication with prolonged high-dose infusion; fetal effects include bradycardia and distress.
  • Anaphylaxis and hypersensitivity reactions have been reported.
  • Compounded intranasal use: nasal irritation or discomfort, headache, transient tiredness or sedation, nausea, irritability or emotional lability (reported in some autism trials), and fluid retention.

Warnings and contraindications

Important safety information. This is not exhaustive — read the full prescribing information and consult your prescriber or pharmacist.

Warnings
  • Based on the FDA-approved labeling for the injectable product, plus the compounded-product context.
  • Boxed warning: oxytocin is not indicated for elective induction of labor (induction without medical indication).
  • It should be used only when medically indicated and under continuous supervision by qualified personnel in a hospital setting with immediate surgical capability.
  • Excessive dosing can cause uterine hyperstimulation, tetanic contractions, uterine rupture, and fetal distress, bradycardia, or death.
  • Because of its antidiuretic effect, prolonged administration with large fluid volumes can cause severe water intoxication with seizures, coma, and death.
  • Postpartum hemorrhage, cardiac arrhythmias, anaphylaxis, and afibrinogenemia have been reported.
  • Compounded intranasal and sublingual oxytocin are not FDA-approved; safety and efficacy for behavioral, mood, or bonding uses have not been established through adequate well-controlled trials, and sterility or formulation risks apply.
  • Peripheral injection does not reliably produce central nervous system effects because of poor blood-brain-barrier penetration.
Contraindications
  • Per the approved labeling: significant cephalopelvic disproportion; unfavorable fetal positions or presentations undeliverable without conversion; obstetrical emergencies favoring surgical intervention; fetal distress where delivery is not imminent; prolonged use in uterine inertia or severe toxemia; hypertonic or hyperactive uterine patterns; contraindicated vaginal delivery (for example, invasive cervical carcinoma, active herpes genitalis, total placenta previa, vasa previa, cord presentation or prolapse); and hypersensitivity to oxytocin.

Reconstitution Steps

How to prepare the lyophilized vial. Confirm specifics with your pharmacist or prescriber.

  1. The FDA-approved product is supplied as a solution and is diluted rather than reconstituted from powder; the steps below describe preparing an infusion. Compounded powder preparations follow the pharmacy's directions.
  2. Confirm the vial strength (commonly 10 USP units per mL) and the ordered dose before starting.
  3. Wash your hands and gather supplies: the oxytocin vial, the compatible IV fluid, an alcohol swab, and a sterile syringe.
  4. Inspect the solution: it should be clear and colorless with no particles. Do not use if cloudy or discolored.
  5. Wipe the vial stopper with a fresh alcohol swab and let it dry.
  6. Draw up the ordered volume of oxytocin.
  7. Add it to the IV fluid bag and rotate the bag gently to mix; do not shake.
  8. Note the resulting concentration (units per mL) for reference and for the infusion pump setting.
  9. Administer by controlled infusion pump under continuous supervision; label the bag with the concentration and time.

US regulatory status

Classifications are public record but can change. For reference only, not legal advice.

DEA scheduleNot a controlled substance
Development stageFDA approved
503A compoundingEligible
503B compoundingEligible

Development: Oxytocin was the first peptide hormone to be sequenced and synthesized, work by Vincent du Vigneaud that earned the 1955 Nobel Prize in Chemistry. The injectable product has long-standing FDA approval for labor induction where medically indicated, labor augmentation, control of postpartum bleeding, and management of incomplete or inevitable abortion, and it is on the WHO essential medicines list. A large separate research literature has examined intranasal oxytocin for social cognition, autism spectrum disorder, PTSD, borderline personality disorder, social anxiety, and depression; results have been mixed and no behavioral indication has been approved, with methodological debate over how much intranasally delivered oxytocin reaches the brain. Compounded intranasal and sublingual oxytocin are widely marketed for bonding, mood, and libido; these uses are off-label and rest on emerging rather than FDA-evaluated evidence.

Notes: Oxytocin's status depends entirely on route. Injectable oxytocin (Pitocin and generics) is FDA-approved for obstetric indications and carries a boxed warning against elective induction of labor. Intranasal oxytocin, sublingual troches, and subcutaneous oxytocin for behavioral or research uses are NOT FDA-approved for any indication; they are lawfully available only as patient-specific compounded preparations from licensed 503A pharmacies under prescription, and are not FDA-evaluated for safety or effectiveness. Over-the-counter oxytocin sprays sold as supplements are not legitimate. Oxytocin is not a controlled substance and is not on the WADA Prohibited List. (Status current as of mid-2026.)

International status

UKApproved (MHRA) as oxytocin injection (e.g., Syntocinon) for obstetric use
EUApproved (national authorities) as oxytocin injection for obstetric use
AustraliaApproved (TGA) as oxytocin injection for obstetric use
CanadaApproved (Health Canada) as oxytocin injection for obstetric use

Pharmacokinetics

Molecular weightApproximately 1,007.2 g/mol (molecular formula C43H66N12O12S2). CAS 50-56-6.
Half-lifeVery short, approximately 1 to 6 minutes in plasma after intravenous administration (reported as short as 3 to 5 minutes), which is why obstetric use is by continuous titrated infusion.
Time to peakUterine response begins within about 1 minute of intravenous infusion and reaches steady state in roughly 20 to 40 minutes; intramuscular effect begins within 3 to 5 minutes. Intranasal delivery produces central effects reported over roughly 30 to 60 minutes in research settings.
ClearanceRapidly cleared by the liver and kidneys and by circulating oxytocinase (placental aminopeptidase), which rises in pregnancy.
SequenceNonapeptide Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2, with a disulfide bridge between cysteine 1 and cysteine 6 forming a six-residue ring and a three-residue tail. It differs from vasopressin at only two positions, which accounts for its mild antidiuretic activity.

Storage and handling

TemperatureStore the approved injectable per its labeling (commonly 20 to 25 degrees C or refrigerated depending on the product); do not freeze. Compounded intranasal formulations are typically refrigerated per the pharmacy.
Light sensitiveProtect from light; some manufacturer instructions specify opaque storage.
Shelf lifePer the manufacturer expiration date for the approved product, or the beyond-use date assigned by the compounding pharmacy.
Reconstituted storageThe approved product is supplied as a solution rather than a powder to reconstitute; for infusion it is diluted into a compatible IV fluid and used promptly. Refrigerate compounded preparations per the pharmacy and discard if cloudy or particulate.

Important Notes

Practical considerations for consistency and safety.

  • Oxytocin's regulatory status is route-dependent: injectable is FDA-approved for obstetric use, while the intranasal and sublingual forms marketed for bonding, mood, and libido are compounded and NOT FDA-approved.
  • The injectable label carries a boxed warning against elective induction of labor.
  • Peripherally injected oxytocin does not reliably reach the brain; expecting central effects from subcutaneous dosing is a common misunderstanding.
  • High-dose or prolonged infusion with large fluid volumes can cause water intoxication because of oxytocin's antidiuretic activity.
  • Oxytocin was the first peptide hormone sequenced and synthesized (Nobel Prize, 1955).

Lifestyle Factors

  • Obstetric use occurs only in a supervised hospital setting with continuous monitoring.
  • Compounded intranasal use is prescriber-directed; intranasal technique matters, since spraying into the throat rather than the nasal mucosa is a common reason for no effect.

Related compounds

Important disclaimer

This page is an educational reference, not medical advice, a diagnosis, or a treatment recommendation, and not a substitute for your prescriber or pharmacist. Approval and regulatory status varies by compound and can change. Always confirm against current prescribing information and consult a qualified healthcare professional before making any decision about a medication.