All information below describes the compound's chemical identity, laboratory handling, and the published research literature. It describes molecular targets and results in laboratory and animal models only — not effects in humans — and is not evidence of any human benefit.
What Is Oxytocin?
Oxytocin is a cyclic nonapeptide composed of nine amino acids (sequence CYIQNCPLG) carrying a C-terminal amide and an intramolecular disulfide bridge between its two cysteine residues (Cys1–Cys6). It is a neurohypophysial hormone originally isolated from the posterior pituitary gland, and its amino acid sequence was determined and the peptide chemically synthesized by du Vigneaud and colleagues in 1953. It occurs endogenously in mammals and is also produced synthetically as a reference compound.
It is supplied as a reference compound for in vitro and animal research use only. The sections below summarize its chemical identity, laboratory handling, the molecular targets and model systems examined in the published literature, and the primary references — without describing outcomes, efficacy, or effects in humans.
Research Targets & Pathways
Published preclinical literature has examined oxytocin in relation to several molecular systems. These are pathway associations reported in laboratory and animal models; refer to the cited studies for methods and findings.
- Oxytocin receptor (OXTR) — a class A (rhodopsin-like) G-protein-coupled receptor examined in ligand-binding and receptor-expression assays.
- Gq/11 – phospholipase C-β signaling — studied downstream of OXTR in inositol-phosphate (IP1/IP3) and intracellular-calcium assays.
- Vasopressin V1a receptor cross-reactivity — characterized in receptor-selectivity and binding studies.
- MAPK/ERK signaling — reported downstream of OXTR activation in certain cell systems.
- Central-amygdala CRF neuron circuits — examined in rodent electrophysiology model systems.
- Hippocampal CA2 OXTR-expressing neurons — investigated in social-memory circuit studies.
Model Systems Studied
Oxytocin has been used as a test compound across a range of published preclinical model systems, primarily in rodents and in vitro cell assays, with additional human intranasal-administration studies. Refer to the cited literature for study designs, endpoints, and findings.
- Social & affiliative behavior — prairie-vole pair-bonding models; rodent social-recognition and social-memory paradigms.
- Fear & anxiety circuits — rodent fear-conditioning models and central-amygdala electrophysiology.
- HPA-axis / stress — rodent and human protocols, including the Trier Social Stress Test with intranasal administration.
- Nociception — rodent spinal tail-flick and hot-plate assay systems.
- In vitro — OXTR-expressing cell lines for binding, cAMP/IP1, and calcium-flux assays; uterine and smooth-muscle contractility preparations.
Note: much of the human intranasal oxytocin literature has shown mixed replication across independent cohorts; interpret the model-system data accordingly.
Stability & Handling
Oxytocin contains an intramolecular disulfide bridge (Cys1–Cys6) that is subject to reduction, and the literature notes that the peptide is susceptible to deamidation and dimerization in aqueous solution, as well as to heat, oxidation, and metal-ion catalysis. These physicochemical properties are relevant to formulation and handling in research settings, where aqueous solutions are typically kept cold, protected from light, and used promptly. Confirm lot-specific integrity by mass spectrometry where disulfide status is critical to an assay.
Molecular & Technical Profile
C43H66N12O12S2 | MW 1007.19 g/mol | CAS 50-56-6 | Sequence: CYIQNCPLG (Cys1–Cys6 disulfide, C-terminal amide)
Storage, Reconstitution & Working Concentrations
Storage, reconstitution, and working-concentration values are general laboratory guidance for in vitro and animal research; always confirm against the lot-specific Certificate of Analysis.
Current Research Status
An approved oxytocin injection product (marketed as Pitocin) exists and is authorized as a prescription drug in various jurisdictions. The material described here is research-grade oxytocin supplied for in vitro and animal laboratory use only — it is not the approved drug product and is not intended for human or clinical use. The broader neuroscience and behavioral literature on oxytocin is largely preclinical, derived from rodent and in vitro models, with human work centered on intranasal-administration protocols whose findings have shown variable replication across independent cohorts. As of the time of this writing, research-grade oxytocin as supplied here has not been approved by the U.S. Food and Drug Administration (FDA) for any human use. Ongoing research continues to characterize the compound's mechanistic profile and identify which experimental findings may have translational relevance.
Research FAQ
Is oxytocin approved for human use?
An approved oxytocin injection product (marketed as Pitocin) exists as a prescription drug in various jurisdictions. The research-grade oxytocin supplied here is a laboratory reference material only — not the approved drug product, and not for human consumption or clinical use.
What is oxytocin's molecular formula and sequence?
A cyclic nonapeptide, sequence CYIQNCPLG with a C-terminal amide and a Cys1–Cys6 disulfide bridge — molecular formula C43H66N12O12S2, MW 1007.19 g/mol, CAS 50-56-6.
How is oxytocin stored and reconstituted?
Store lyophilized at −20°C, desiccated and protected from light. Reconstitute in sterile or bacteriostatic water (or dilute acetic acid); store the reconstituted solution at 2–8°C for up to ~28 days and avoid repeated freeze–thaw.
What targets and model systems has oxytocin been studied in?
Preclinical work has characterized the oxytocin receptor (OXTR) and its Gq/phospholipase C signaling, with vasopressin V1a cross-reactivity, across prairie-vole pair-bonding, rodent fear-conditioning and social-memory paradigms, and OXTR-expressing cell assays. Note the mixed replication of the human intranasal literature noted above.
Selected References
- du Vigneaud V, Ressler C, Trippett S. (1953). The sequence of amino acids in oxytocin, with a proposal for the structure of oxytocin. Journal of Biological Chemistry, 205(2):949–957.
- Gimpl G, Fahrenholz F. (2001). The oxytocin receptor system: structure, function, and regulation. Physiological Reviews, 81(2):629–683.
- Kosfeld M, Heinrichs M, Zak PJ, Fischbacher U, Fehr E. (2005). Oxytocin increases trust in humans. Nature, 435(7042):673–676.
- Domes G, Heinrichs M, Michel A, Berger C, Herpertz SC. (2007). Oxytocin improves "mind-reading" in humans. Biological Psychiatry, 61(6):731–733.
- Ross HE, Young LJ. (2009). Oxytocin and the neural mechanisms regulating social cognition and affiliative behavior. Frontiers in Neuroendocrinology, 30(4):534–547.
- Knobloch HS, et al. (2012). Evoked axonal oxytocin release in the central amygdala attenuates fear response. Neuron, 73(3):553–566.