PT-141 vs Kisspeptin vs Oxytocin Nasal Spray: Three Libido Research Pathways
PT-141, Kisspeptin and oxytocin are studied on three different libido pathways: PT-141 (bremelanotide) acts on melanocortin receptors in the brain’s desire circuits, Kisspeptin sits at the top of the reproductive hormone axis, and oxytocin is the hormone of bonding and trust. Vistara Labs sells all three as ready-mixed nasal sprays in a sealed metered pump (0.175 mL per press), and combines them as the Libido Spray Stack (PT-141 and oxytocin) and the Libido Trifecta Spray Stack (all three).
At a glance: PT-141 sprays in 10 mg and 20 mg sizes, a 10 mg Kisspeptin spray, oxytocin sprays in 2 mg, 4 mg and 10 mg sizes, and two libido spray stacks, all with certificates of analysis on our Lab Reports page, shipped from within Canada by Canada Post Xpresspost, with same-business-day dispatch on orders placed before 3 pm Pacific, Monday to Friday.
Findings
- In healthy men and men with erectile dysfunction, intranasal PT-141 produced a statistically significant erectile response compared with placebo and was well tolerated (Diamond, Int J Impot Res, 2004).
- In 32 men with hypoactive sexual desire disorder, kisspeptin modulated brain activity across the sexual-processing network and raised penile tumescence by up to 56% more than placebo (Mills, JAMA Netw Open, 2023).
- In 32 women with hypoactive sexual desire disorder, kisspeptin modulated sexual and facial-attraction brain processing and was well tolerated with no reported adverse effects (Thurston, JAMA Netw Open, 2022).
- Intranasal oxytocin caused a substantial increase in trust between people, specifically in the willingness to accept social risks (Kosfeld, Nature, 2005).
PT-141 vs Kisspeptin vs oxytocin: how do they compare?
| PT-141 Nasal Spray | Kisspeptin Nasal Spray | Oxytocin Nasal Spray | |
|---|---|---|---|
| Pathway | Melanocortin (MC3 and MC4 receptors) | Reproductive hormone axis (KISS1 receptor, GnRH, LH and FSH) | Oxytocin receptor, social bonding |
| Studied for | Desire and arousal in men and women | Hormone balance, fertility, libido and sexual brain processing | Trust, attachment, the stress response and relaxation |
| In the bottle | 10 mg in 5 mL, or 20 mg in 10 mL | 10 mg in 5 mL | 2 mg in 5 mL, 4 mg in 10 mL, or 10 mg in 10 mL |
| Sprays and amount per spray | About 28 or 57, 350 mcg each | About 28, 350 mcg each | About 29 or 57 at about 70 mcg; about 57 at about 175 mcg (10 mg) |
| In a stack | Libido and Libido Trifecta | Libido Trifecta | Libido and Libido Trifecta (2 mg or 10 mg) |
Every bottle arrives pre-mixed in sterile saline in a sealed metered atomiser, so there is nothing to reconstitute and no bacteriostatic water to buy. Our page on sprays per bottle shows how each figure is worked out.
What is the difference between PT-141, Kisspeptin and oxytocin?
Where each acts. Kisspeptin works upstream, prompting the release of LH and FSH, which drive sex-hormone production. PT-141 works centrally on melanocortin receptors linked to desire and arousal, and not on blood flow. Oxytocin works on the bonding side: trust, attachment and the emotional state around intimacy. All three have human research behind the nasal route: PT-141 in its early trials, oxytocin in most of its published work, and Kisspeptin since a 2025 study showed it is delivered effectively by nasal spray and rapidly raises luteinising hormone (Mills, EBioMedicine, 2025).
What is PT-141 best suited to study?
PT-141 (bremelanotide) suits designs on the desire and arousal response itself. In 18 premenopausal women with sexual arousal disorder, more women reported moderate or high sexual desire after a single intranasal administration than after placebo, and among those who attempted intercourse within 24 hours, significantly more were satisfied with their arousal (Diamond, J Sex Med, 2006). In the men’s study, the first erection came at about 30 minutes (Diamond, 2004).
More: Buy PT-141 Nasal Spray in Canada and How Long Does PT-141 Last?
What is Kisspeptin best suited to study?
Kisspeptin suits designs that include the reproductive hormone axis and the brain processing of sexual cues. In the men’s trial it also increased behavioural measures of sexual desire, most notably happiness about sex (Mills, 2023). In the women’s trial, kisspeptin’s enhancement of posterior cingulate activity in response to attractive faces correlated with reduced sexual aversion (Thurston, 2022). The intranasal study found it stable in a nasal spray for up to 60 days at 4 °C (Mills, 2025).
More: Buy Kisspeptin Nasal Spray in Canada and Kisspeptin vs HCG: How They Differ.
What is oxytocin best suited to study?
Oxytocin suits designs on bonding, partner interaction and the experience after intimacy. In 29 healthy couples, intranasal oxytocin increased the intensity of orgasm and contentment after intercourse; men reported higher sexual satiety, and women felt more relaxed (Behnia, Horm Behav, 2014). Its three bottle sizes give a choice between about 70 mcg and about 175 mcg per spray.
More: Buy Oxytocin Nasal Spray in Canada and Oxytocin Nasal Spray vs Injection.
Can PT-141, Kisspeptin and oxytocin be studied together?
Yes. Because each works on a different pathway, they combine rather than overlap. The Libido Spray Stack bundles two ready-mixed sprays:
- 10 mg PT-141 Nasal Spray: the melanocortin arm, studied for central desire pathways and arousal.
- 2 mg or 10 mg Oxytocin Nasal Spray: the bonding arm, studied for trust, attachment and the stress response.
The Libido Trifecta Spray Stack adds the third pathway:
- 10 mg Kisspeptin Nasal Spray: the upstream hormonal signal, studied for GnRH, LH and FSH release and arousal circuits.
See Buy the Libido Spray Stack in Canada, Buy the Libido Trifecta Spray Stack in Canada and our libido peptide nasal sprays guide.
Where to buy PT-141, Kisspeptin and oxytocin nasal sprays in Canada
- No customs step. Every order ships from within Canada, so the spray travels as an ordinary domestic parcel.
- Same-day dispatch. Orders placed before 3 pm Pacific, Monday to Friday, leave the same business day by tracked Canada Post Xpresspost.
- Keep it cold. Like any peptide in solution, the spray is kept refrigerated once it arrives; see How to Store a Peptide Nasal Spray.
- Prefer powder? The lyophilised PT-141 10 mg vial, Kisspeptin 10 mg vial and Oxytocin 2 mg vial are also available.
- The full range. Our guide to peptide nasal sprays in Canada lists every spray we carry; see also the best peptide nasal sprays in Canada and, for focus and calm, the nootropic peptide nasal sprays.
PT-141, Kisspeptin and oxytocin are supplied for laboratory research use only. The human studies above were clinical research using pharmaceutical preparations under medical supervision.
Frequently asked questions
What is the difference between PT-141, Kisspeptin and oxytocin?
PT-141 acts on melanocortin receptors in the brain’s desire pathways. Kisspeptin is the upstream hormone that prompts LH and FSH release. Oxytocin is the hormone studied for bonding, trust and the stress response.
Which is studied most for sexual desire?
PT-141 and Kisspeptin both have human studies on sexual desire: PT-141 on desire and arousal responses, and Kisspeptin on sexual brain processing in hypoactive sexual desire disorder.
How much is in each spray?
PT-141 and Kisspeptin deliver 350 mcg per spray. Oxytocin delivers about 70 mcg per spray in the 2 mg and 4 mg bottles and about 175 mcg in the 10 mg bottle.
Which spray stack contains all three?
The Libido Trifecta Spray Stack: a 10 mg Kisspeptin spray, a 10 mg PT-141 spray and a 2 mg or 10 mg oxytocin spray. The Libido Spray Stack contains PT-141 and oxytocin only.
Do these nasal sprays need mixing?
No. All three arrive ready-mixed in sterile saline in a sealed metered pump that delivers 0.175 mL per press, so there is nothing to reconstitute.
Where can I buy PT-141, Kisspeptin and oxytocin nasal sprays in Canada?
Vistara Labs ships all three sprays and both libido spray stacks from within Canada by Canada Post Xpresspost, with same-business-day dispatch on orders placed before 3 pm Pacific, Monday to Friday.
Product details from vistaralabs.ca, October 2026. Sources: Diamond LE et al. Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction. Int J Impot Res. 2004. PMID 14963471. Diamond LE et al. An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist. J Sex Med. 2006. PMID 16839319. Mills EG et al. Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open. 2023. PMID 36735255. Thurston L et al. Effects of Kisspeptin Administration in Women With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open. 2022. PMID 36287566. Mills EG et al. Intranasal kisspeptin administration rapidly stimulates gonadotropin release in humans. EBioMedicine. 2025. PMID 40215751. Kosfeld M et al. Oxytocin increases trust in humans. Nature. 2005. PMID 15931222. Behnia B et al. Differential effects of intranasal oxytocin on sexual experiences and partner interactions in couples. Horm Behav. 2014. PMID 24503174.
More on this: PT-141 vs Kisspeptin: How They Differ, PT-141 vs Oxytocin: How They Differ and Kisspeptin vs Oxytocin: How They Differ.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
