Oxytocin
A nine-residue neurohypophysial hormone with a well-characterised receptor and one of the largest literatures of any peptide in the catalogue.
- Purity
- 99.2%
- Lot
- PU-C1B1
- Format
- Lyophilized powder
- Third-party tested
- Discreet packaging
- Same-day shipping
- Encrypted checkout
For research use only. Not for human consumption.
Mechanism of Action
Oxytocin is a cyclic nonapeptide produced in the hypothalamus and released from the posterior pituitary. It acts at a single characterised G-protein-coupled receptor whose structure, signalling and regulation were reviewed in Physiological Reviews in 2001 and again in 2018.
The receptor couples through Gq in the myometrium, producing the contractile response that underlies its obstetric use, while central oxytocin signalling has been examined separately in the context of neural plasticity and social behaviour. Reviews caution that peripheral and central pharmacology are not interchangeable.
Research Findings
The obstetric and pharmacological literature is mature, reviewed in the American Journal of Obstetrics and Gynecology in 2024 and in Pharmacological Reviews in 2020, the latter explicitly questioning the breadth of claims made for the peptide.
The behavioural literature - reviewed in the Annual Review of Neuroscience, Endocrinology and Biological Psychiatry - has repeatedly revised its own conclusions, with the social salience hypothesis offered as an alternative to simpler accounts.
Storage & Reconstitution
Sealed lyophilized vials are stored in the dark. The peptide-formulation literature regards the dry solid as the stable state and the solution as the fragile one: refrigeration at 2-8 degrees C is standard for short holding periods, and minus 20 degrees C or colder for long-term storage. Vials are brought to room temperature before opening so that atmospheric moisture does not condense onto the cold solid.
For reconstitution, the diluent is added slowly down the inner wall of the vial rather than directly onto the cake, and the vial is swirled rather than shaken - agitation at an air-liquid interface is a well-documented driver of peptide aggregation. The solid should dissolve to a clear, particle-free solution; persistent cloudiness or visible particulate indicates the material should not be used.
Reconstituted solution is held at 2-8 degrees C and protected from light. Freeze-thaw cycling is the single most avoidable cause of loss, so where a solution must be frozen it is aliquoted first into single-use volumes. Working aliquots are labelled with the lot number so that any result can be traced back to the certificate of analysis for that lot.
- Physical form
- Lyophilized powder, sealed vial
- Sealed storage
- 2-8 C short term / -20 C long term
- Reconstituted
- 2-8 C, protected from light
- Diluent
- Bacteriostatic water, added down the vial wall
- Avoid
- Shaking, freeze-thaw cycling, direct light
Handling summary
References
Every entry below links to its PubMed record. Publication is not endorsement: several of these papers report limitations, negative findings or adverse events, and they are listed for that reason.
- [1]Oxytocin, Neural Plasticity, and Social Behavior(opens PubMed in a new tab)
Annu Rev Neurosci · 2021 · PMID 33823654
- [2]The physiology and pharmacology of oxytocin in labor and in the peripartum period(opens PubMed in a new tab)
Am J Obstet Gynecol · 2024 · PMID 38462255
- [3]Oxytocin, Vasopressin, and Social Behavior: From Neural Circuits to Clinical Opportunities(opens PubMed in a new tab)
Endocrinology · 2022 · PMID 35863332
- [4]The Oxytocin Receptor: From Intracellular Signaling to Behavior(opens PubMed in a new tab)
Physiol Rev · 2018 · PMID 29897293
- [5]The oxytocin receptor system: structure, function, and regulation(opens PubMed in a new tab)
Physiol Rev · 2001 · PMID 11274341
- [6]Is Oxytocin "Nature's Medicine"?(opens PubMed in a new tab)
Pharmacol Rev · 2020 · PMID 32912963