A quiet analytical research laboratory at night, racks of glass vials along a dim bench.

Oxytocin and Kisspeptin

Oxytocin is an approved prescription drug for obstetric use, given by infusion or injection under medical supervision. Kisspeptin is an investigational peptide with no approved human use and is named on the WADA Prohibited List. Both are short peptides with half-lives of minutes, which is why the nasal route recurs in research on them.

Molecular class and size

Oxytocin is a nonapeptide (Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2, about 1,007 Da) with a disulfide bridge between the two cysteines forming a six-residue ring. It is made in the hypothalamus and released from the posterior pituitary. Kisspeptins are a family of peptides cleaved from the KISS1 gene product, including kisspeptin-54, -14, -13 and -10; kisspeptin-10 is a decapeptide of about 1,302 Da and carries the C-terminal sequence required for receptor activity. Both are hydrophilic and cleared from plasma within minutes.

Regulatory status and anti-doping

Oxytocin is approved by the FDA as Pitocin and marketed as Syntocinon in many other jurisdictions, for induction or augmentation of labor and control of postpartum bleeding, administered intravenously or intramuscularly under medical supervision. Other uses, including intranasal use, are unapproved or research only. Kisspeptin has been studied in early-phase human research, mainly in reproductive endocrinology, and has no marketing authorization from the FDA, EMA or Health Canada. WADA names kisspeptin and its agonists in section S2.2.1, prohibited at all times for male athletes. Oxytocin is not named on the Prohibited List. Vegalab does not supply either peptide.

Why intranasal delivery matters for small neuropeptides

Neither peptide crosses the blood-brain barrier efficiently from the bloodstream, and both are degraded quickly by plasma and tissue peptidases. The nasal route offers olfactory and trigeminal pathways to the central nervous system that partly bypass the barrier. In practice, very little of a nasal dose reaches the brain: mucociliary clearance removes nasal mucus with a half-time of roughly 15 to 20 minutes, nasal peptidases cleave unprotected peptides, and much of the dose is swallowed or absorbed systemically. Published reviews have questioned how much intranasal oxytocin reaches the brain at the doses used in research.

How mucoadhesive encapsulation addresses it

A cationic mucoadhesive outer layer, such as chitosan, binds mucin and increases residence time at the olfactory region, and chitosan transiently widens tight junctions to raise paracellular transport of hydrophilic molecules. Inner layers restrict peptidase access and can protect the oxytocin disulfide bond from reduction until release. These are general principles of nasal peptide delivery, not evidence of any effect for either compound, and any application would sit within a licensed developer's regulated clinical program.

Key facts

Oxytocin injection is FDA approved as Pitocin for antepartum and postpartum obstetric indications (FDA label, Pitocin)
Kisspeptin and its agonists are named in section S2.2.1 of the WADA Prohibited List (WADA Prohibited List, current edition)
Kisspeptin-10 has a plasma half-life of about 4 minutes versus about 28 minutes for kisspeptin-54 (Jayasena et al. 2015, Hum Reprod)
Central delivery of intranasal oxytocin at research doses has been questioned (Leng and Ludwig 2016, Biol Psychiatry)
Intranasal delivery can reach the central nervous system through olfactory and trigeminal pathways (Lochhead and Thorne 2012, Adv Drug Deliv Rev)

How our delivery technology applies

For 1 to 1.3 kDa hydrophilic peptides, the nasal problem is residence time, peptidase exposure and, for oxytocin, disulfide integrity. A multi-layer particle with a chitosan-class outer layer anchors to mucin, while inner layers limit enzyme contact and hold the payload until it reaches the epithelium. We describe this as platform capability for licensed pharmaceutical partners only, not as a product.

Licensed pharmaceutical developers can request a technical call on nasal peptide carriers.