# Oxytocin

> Evidence tier S — Approved · Hormones & Drive · reviewed 2026-11-08
> Source page: https://peptidemeta.com/p/oxytocin/

Also known as: Pitocin, Syntocinon

## Quick answers

**What is Oxytocin?**

The endogenous "bonding hormone" produced in the hypothalamus, used therapeutically for labor induction and explored for social cognition, anxiety, and pair-bonding enhancement.

**How strong is the evidence for Oxytocin?**

Tier S (approved) on the peptidemeta evidence scale. FDA-approved injectable drug (Pitocin and generics) used in obstetrics. Intranasal use for social or psychiatric effects is investigational.

**Is Oxytocin FDA-approved?**

Yes. The FDA approved Oxytocin (Pitocin). Approved to induce or strengthen uterine contractions and to control bleeding after delivery.

**Is Oxytocin banned in sport?**

No. Oxytocin is not on the World Anti-Doping Agency Prohibited List.

**How does Oxytocin work?**

Oxytocin is a nine-amino-acid neuropeptide synthesized in hypothalamic paraventricular and supraoptic nuclei that binds the oxytocin receptor (OXTR), a Gq-coupled GPCR. In the brain, it modulates amygdala reactivity and promotes social approach behavior.

**What is known about the safety of Oxytocin?**

FDA-approved (Pitocin) for labor induction with well-established safety profile. Intranasal use for social/cognitive effects is off-label.

## Key facts

- **Evidence tier:** S (Approved)
- **FDA:** approved (Pitocin)
- **WADA:** not on the Prohibited List
- **Peptide:** yes
- **Sequence:** CYIQNCPLG[NH2] (9 residues)
- **Formula:** C43H66N12O12S2
- **Molecular weight:** 1007.2 g/mol
- **Discovered:** 1953 — Vincent du Vigneaud determined its structure and synthesized it, the first polypeptide hormone ever synthesized (Nobel Prize in Chemistry, 1955).
- **Routes studied:** Intranasal, Subcutaneous, Intravenous

## Overview

The endogenous "bonding hormone" produced in the hypothalamus, used therapeutically for labor induction and explored for social cognition, anxiety, and pair-bonding enhancement.

## Mechanism

Oxytocin is a nine-amino-acid neuropeptide synthesized in hypothalamic paraventricular and supraoptic nuclei that binds the oxytocin receptor (OXTR), a Gq-coupled GPCR. In the brain, it modulates amygdala reactivity and promotes social approach behavior. Peripherally, it stimulates uterine smooth muscle contraction and mammary gland myoepithelial cell contraction for milk letdown.

## Effects reported in research

_Reported outcomes, not promises; see the evidence tier._

- Enhanced social bonding and trust
- Reduced social anxiety
- Improved emotional recognition
- Supported lactation and uterine contractions (clinical use)

## Safety & unknowns

FDA-approved (Pitocin) for labor induction with well-established safety profile. Intranasal use for social/cognitive effects is off-label. Side effects: headache, nasal irritation (intranasal), water retention at high doses. Avoid in pregnancy unless for labor induction under medical supervision.

## Studies

- Riem MM, Bakermans-Kranenburg MJ, Pieper S, et al. (2011). *Oxytocin modulates amygdala, insula, and inferior frontal gyrus responses to infant crying: a randomized controlled trial*. Biological Psychiatry. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/21470595/
  Randomized controlled fMRI study in which intranasal oxytocin reduced amygdala activation and increased insula and inferior frontal gyrus responses to infant crying.

## Status sources

- [Drugs@FDA — NDA 018261 (Pitocin)](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=018261)
- [DailyMed — Pitocin (oxytocin injection) label](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6d4b2c25-2e5d-49b5-93bc-2ae8a20916d1)
- [PubChem CID 439302 (oxytocin)](https://pubchem.ncbi.nlm.nih.gov/compound/439302)
- [Nobel Prize in Chemistry 1955 — du Vigneaud](https://www.nobelprize.org/prizes/chemistry/1955/summary/)
- [WADA 2026 Prohibited List (oxytocin not named)](https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf)

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Educational reference only — not medical advice. No dosing information is published. Tiers rate the strength of published evidence, not effectiveness or safety.