Neuropeptides Peptide Hormones Approved

Oxitocina

Also known as: Oxytocin, Pitocin, Syntocinon

Oxytocin is a nine-amino-acid peptide hormone produced in the hypothalamus and released by the posterior pituitary. It regulates uterine contraction during labor and milk ejection during lactation, and acts as a neuromodulator involved in social bonding, trust and affiliative behavior. It is an approved drug (FDA/EMA) for obstetric use.

Mechanism of action

Oxytocin acts on the oxytocin receptor (OXTR), coupled to Gq protein.

Uterine smooth muscle: activates phospholipase C, raises intracellular calcium and triggers contraction.
Mammary gland: contracts myoepithelial cells, inducing milk ejection.
CNS: modulates the amygdala and reward circuits, influencing social bonding and stress response.

Uses & indications

Labor induction and augmentation (approved use).
Postpartum hemorrhage control.
Research on social bonding, autism and anxiety (intranasal, experimental).

Effects

Effects: uterine contraction, milk ejection and, centrally, increased trust and social behavior.

Adverse effects: with obstetric use, uterine hyperstimulation, arrhythmias, nausea and, at high doses, hyponatremia due to its antidiuretic effect. Intranasal route: nasal irritation.

Considerations & contraindications

Obstetric use always under medical supervision and monitoring.
"Social" intranasal use is experimental and not approved.
Risk of fluid retention/hyponatremia with high doses or fluids.

Regulatory approval

Approved by FDA and EMA for labor induction and postpartum hemorrhage (Pitocin, Syntocinon). Behavioral intranasal use is not approved.

Dosage

Clinical use is strictly hospital-based and dosed by healthcare staff. A self-administration regimen is not appropriate.

Storage

Pharmaceutical vial: 2–8 °C per label. Research lyophilized: 2–8 °C; reconstituted, refrigerate and use within days.

Technical data

Regulatory status Approved

Molecular weight 1007.19 Da

Half-life 1–6 minutos (plasma)

Administration routes Intravenosa, intramuscular, intranasal (experimental)