Oxytocin (5 mg)

Neuropeptide Hormone / Social Bonding Modulator / Uterotonic Research Agent

Oxytocin is a cyclic nonapeptide hormone (nine amino acids) produced in the hypothalamus and released via the posterior pituitary. As a biological ligand for the oxytocin receptor (OXTR)—a G-protein–coupled receptor (GPCR)—oxytocin plays key roles in social behavior, maternal bonding, stress regulation, autonomic control, smooth muscle contraction, and neuroendocrine signaling.

In laboratory research, oxytocin is extensively used to study:

• Social cognition and affiliative behavior

• Stress reactivity and HPA-axis modulation

• Pair-bonding and maternal behaviors

• Anxiety, fear extinction, and emotional regulation

• Receptor pharmacology and GPCR calcium signaling

• Myometrial and mammary gland contractility

Oxytocin (5 mg) supplied as lyophilized powder is intended strictly for experimental research, not for clinical or reproductive use.

Specifications

Synonyms: Oxytocin, OXT, α-hypophamine, oxytocic peptide
Sequence: Cys–Tyr–Ile–Gln–Asn–Cys–Pro–Leu–Gly–NH₂
Structure: Cyclic nonapeptide with disulfide bridge between Cys¹ and Cys⁶
Molecular Formula: C₄₃H₆₆N₁₂O₁₂S₂
Molecular Weight: ~1007.2 g/mol
Class: Neuropeptide hormone / OXTR agonist
Presentation: Lyophilized powder, 5 mg per vial, >98% purity (research grade)

Mechanism of Action and Signaling Pathways

Oxytocin binds to the OXTR receptor, a Gq-coupled GPCR widely expressed in:

• Limbic brain regions (amygdala, nucleus accumbens, hippocampus)

• Hypothalamus

• Uterus and cervix

• Mammary gland

• Cardiovascular and gastrointestinal tissues

Primary signaling mechanisms

OXTR activation triggers:

• Phospholipase C (PLC) activation

• Increased IP₃ and DAG

• Intracellular Ca²⁺ mobilization

• Activation of protein kinase C (PKC)

• Modulation of downstream transcriptional responses

This Ca²⁺-dependent pathway drives oxytocin’s well-characterized effects on smooth muscle contraction, neurotransmission, and behavioral modulation.

Neuroscience, Social Behavior, and Stress Research

1. Social bonding and affiliative behavior

Oxytocin plays a critical role in:

• Pair bonding

• Trust and prosocial behavior

• Social memory formation

• Maternal care and attachment

Human and animal studies consistently show that oxytocin modulates neural circuits involved in reward, emotion regulation, and social salience, particularly in the amygdala and striatum.

2. Anxiety reduction and fear extinction

OXTR activation in the amygdala and prefrontal cortex:

• Reduces anxiety-like behavior

• Facilitates extinction of conditioned fear

• Dampens stress-induced autonomic responses

3. HPA-axis modulation

Oxytocin inhibits hypothalamic CRH release, resulting in:

• Decreased cortisol levels

• Lower physiological stress reactivity

These properties make oxytocin a key research tool in psychoneuroendocrinology.

Peripheral Physiologic and Cellular Effects

1. Myometrial contraction

Oxytocin’s classical physiological effect is:

• Potent contraction of uterine smooth muscle

• Increased frequency and force of myometrial activity

• Synergistic activity with prostaglandins

2. Mammary gland ejection reflex

Oxytocin causes contraction of:

• Myoepithelial cells → promoting milk ejection in lactation research models

3. Cardiovascular, metabolic and repair biology

Emerging studies show oxytocin’s peripheral effects:

• Enhanced lipid metabolism in some models

• Stimulation of glucose uptake in muscle cells

• Support of wound healing via fibroblast migration and angiogenesis

• Vasodilation and blood-pressure modulation

These findings have opened research into oxytocin’s roles beyond classical reproductive physiology.

Behavioral, Cognitive, and Psychiatric Research Applications

Oxytocin is studied in models of:

• Autism spectrum disorders

• Social anxiety disorder

• PTSD and trauma-related stress

• Addictive behaviors

• Depression and anhedonia

• Maternal-infant bonding deficits

Oxytocin’s ability to modulate neural salience and reward pathways makes it a unique neuropeptide in behavioral research.

Safety, Regulatory Constraints, and Limitations

• Oxytocin is clinically approved only for obstetric indications (labor induction, postpartum hemorrhage control) — not applicable to research-grade material.

• Research-grade oxytocin is not for human, veterinary, obstetric or lactation-related use.

• Potential physiological effects (contextual, not applicable to research use): uterine contractions, hypotension, tachycardia, hyponatremia with excessive synthetic exposure.

• Behavioral effects can be context-dependent and vary with individual neurobiology, making interpretation complex in translational studies.

Research Use Only – Important Notice

This Oxytocin (5 mg) product is supplied exclusively for laboratory research.

• Not for human or veterinary use

• Not for obstetric, reproductive, lactation, or diagnostic purposes

• Intended solely for in vitro studies and controlled animal experiments

• All descriptions summarize findings from preclinical and neuroendocrine literature

• Not to be interpreted as medical advice or dosing guidance

References (Non-Wikipedia, peer-reviewed, with links)

1. Gimpl G, Fahrenholz F. The oxytocin receptor system: structure, function, and regulation. Physiol Rev.
   https://pubmed.ncbi.nlm.nih.gov/10893428/

Bethlehem RAI et al. Oxytocin, brain function and social behavior. Trends Cogn Sci.
https://pubmed.ncbi.nlm.nih.gov/28709791/

Carter CS. Neurobiology of oxytocin and social bonding. Ann N Y Acad Sci.
https://pubmed.ncbi.nlm.nih.gov/20669238/

Neumann ID, Landgraf R. Balance of brain oxytocin and vasopressin: anxiety, social behavior and stress. Trends Neurosci.
https://pubmed.ncbi.nlm.nih.gov/17055261/

Lee HJ et al. Oxytocin in anxiety and fear modulation. Prog Brain Res.
https://pubmed.ncbi.nlm.nih.gov/21802454/

Arrowsmith S, Wray S. Myometrial physiology and oxytocin signaling. Exp Physiol.
https://pubmed.ncbi.nlm.nih.gov/20959341/

Plante E et al. Oxytocin receptor signaling in cardiac tissue. Peptides.
https://pubmed.ncbi.nlm.nih.gov/19596346/

Gouin JP et al. Oxytocin and wound healing research. Psychoneuroendocrinology.
https://pubmed.ncbi.nlm.nih.gov/22244759/