Oxytocin Testing
MW: 1007.19 g/molHalf-life: ~3–6 minutes (rapid plasma degradation)Status: FDA-approved
Cyclic nonapeptide; reproductive and social-bonding research.
Mechanism of action
Cyclic nonapeptide produced by hypothalamus, released from posterior pituitary. Drives uterine contraction (labor), milk ejection, and social/pair-bonding behaviors. Receptor (OXTR) is a Gq-coupled GPCR.
Sequence & structure
Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH₂ (cyclic via Cys1-Cys6 disulfide)
Disulfide-cyclized; cyclization confirmation is the primary identity check.
Research areas
- ●Labor induction (FDA-approved Pitocin)
- ●Autism spectrum / social cognition research
- ●Postpartum hemorrhage
- ●Pair bonding and attachment biology
What we test on Oxytocin
RP-HPLC, intact mass under non-reducing conditions (confirms disulfide intact), endotoxin.
Standard Hormones Panel
- ✓Chiral HPLC (enclomiphene)
- ✓LC-MS
- ✓Potency by ELISA where appropriate
Common impurities & failure modes
- Linear (reduced) oxytocin
+2 Da; failed cyclization or storage reduction.
- Deamidation isomers (Asn5, Gln4)
Common stability indicators.
- Dimers via intermolecular disulfide
Particularly in concentrated solutions.
Regulatory status
FDA-approved (Pitocin, Syntocinon).
Related Hormones peptides
Enclomiphene
405.96 g/mol
Trans-isomer of clomiphene citrate (SERM); secondary hypogonadism research.
HCG (Human Chorionic Gonadotropin)
~36.7 kDa
Glycoprotein hormone of pregnancy; used in fertility and TRT support research.
HMG (Human Menopausal Gonadotropin)
~30 kDa each
FSH + LH combined; fertility research.
Kisspeptin
1302.46 g/mol
Master regulator of GnRH/HPG axis (often as Kisspeptin-10).
VIP (Vasoactive Intestinal Peptide)
3326.78 g/mol
28-residue neuropeptide affecting smooth muscle and immune function.