Oxytocin

Oxytocin in Canada is supplied by Horizon Peptides as a lyophilized powder in sealed research vials, stocked in 2 mg and 5 mg sizes with single-vial, 3-vial and 10-vial pack options. Oxytocin is a nine-residue neuropeptide studied in receptor signalling research.

Oxytocin is a nonapeptide, Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2, with a molecular weight of 1007.19. Its two cysteine residues form a disulfide bridge, closing the first six residues into a ring with a three-residue tail extending from it.

It holds a particular place in peptide chemistry history: it was the first polypeptide hormone to be chemically synthesised, work that established much of the methodology the field still relies on. That heritage is why it appears so often as a benchmark compound in method development.

It differs from vasopressin, a closely related nonapeptide, at only two positions. The pair are a standard teaching example of how minimal sequence differences produce distinct receptor selectivity, and they remain a common control pairing in binding studies.

Research using it concerns receptor binding and neuropeptide signalling in cell-culture and animal models.