Libido

Lead

The libido category covers two peptides operating on completely different upstream pathways: PT-141 (Bremelanotide), a centrally acting melanocortin-receptor agonist, and Kisspeptin-10, the neuroendocrine signal that gates GnRH release at the top of the HPG axis. Together they let researchers interrogate sexual-response physiology from two entirely separate angles — central nervous-system arousal signalling and gonadotropin-axis activation. Both ship lyophilized from a Canadian fulfillment facility with a third-party Certificate of Analysis. The category is small but scientifically distinct.

Mechanism Overview

Sexual response is a product of central neural arousal pathways and downstream gonadal-hormone signalling. The two peptides in this category address each.

PT-141 (Bremelanotide) is a synthetic cyclic heptapeptide derived from α-MSH, with selective agonist activity at the MC4 receptor (with additional MC1 affinity). MC4 receptors are densely expressed in the paraventricular nucleus of the hypothalamus, where their activation triggers downstream pro-erectile and pro-arousal signalling that operates independently of the vascular pathway targeted by PDE5 inhibitors. Pfaus and colleagues’ rodent neurobehavioural work — and the FDA-registration trials for the human formulation Vyleesi — established the central-nervous-system mechanism of action distinct from peripheral vasodilators (Pfaus et al., 2007, J Sex Med).

Kisspeptin-10 is the C-terminal decapeptide fragment of the KISS1 gene product, the master regulator of GnRH neurons in the arcuate nucleus and AVPV. The discovery of Kiss1/GPR54 signalling (de Roux 2003; Seminara 2003) reframed reproductive endocrinology — kisspeptin sits upstream of GnRH, LH, FSH, and downstream sex-steroid production. Imperial College London’s reproductive-endocrinology group (Dhillo et al.) has published the most extensive human pharmacology data on kisspeptin’s effects on the HPG axis.

The two peptides therefore allow researchers to separate central arousal signalling (PT-141) from gonadotropin-axis activation (Kisspeptin-10).

Featured Products

PT-141 / Bremelanotide (10 mg) — Cyclic heptapeptide MC4-receptor agonist studied for central-nervous-system arousal signalling and melanocortin-pathway research. Reconstitutes cleanly at 1 mg/mL in bacteriostatic water; typical research dosing follows 0.5–2 mg ranges from published protocols.

Kisspeptin-10 (5 mg) — Decapeptide C-terminal fragment of KISS1 used in GnRH-pulse and HPG-axis research. Studied at low microgram-per-kilogram doses in Imperial College’s published reproductive-endocrinology protocols.

Research Applications

Investigators use this category to interrogate questions such as: how does MC4-receptor activation alter paraventricular-nucleus signalling in rodent neurobehavioural arousal models; what is the dose–response curve for PT-141 on copulatory-behaviour endpoints; does Kisspeptin-10 administration produce measurable LH pulses across different reproductive-stage models (pubertal, adult, menopausal); how do kisspeptin and GnRH compare on gonadotropin-amplitude endpoints; and can melanocortin signalling be pharmacologically separated from the vascular-mediated effects of PDE5 inhibitors. The category also supports translational reproductive-endocrinology work — modelling hypothalamic amenorrhea, delayed puberty, and hypogonadotropic-hypogonadism mechanisms. A growing line of research uses kisspeptin as a pharmacological probe for polycystic-ovary-syndrome pathophysiology and for functional-hypothalamic-amenorrhea models, while PT-141 is frequently paired with imaging paradigms (fMRI, PET) to localize the central arousal substrate.

Safety & Handling

Reconstitute PT-141 and Kisspeptin-10 with bacteriostatic water using sterile technique. After reconstitution, refrigerate at 2–8 °C and use within 28 days. Lyophilized vials stored at –20 °C are stable for 24+ months. PT-141 may produce transient solution discoloration in some lots — this is consistent with the heptapeptide’s chromophoric profile and does not indicate degradation, but researchers should document lot-by-lot. Both compounds are sold for in-vitro and laboratory research only; they are not intended for human or veterinary use.

FAQ

How does PT-141 differ mechanistically from PDE5 inhibitors? PT-141 acts centrally on MC4 receptors in the hypothalamus to drive arousal signalling, while PDE5 inhibitors act peripherally by preserving cGMP in vascular smooth muscle. The two operate on entirely separate pathways — central neural drive versus peripheral vasodilation.

Is Bremelanotide the same as PT-141? Yes — Bremelanotide is the INN (international non-proprietary name) for the molecule originally designated PT-141. It is the same cyclic heptapeptide.

Why is Kisspeptin classified as a libido peptide? Kisspeptin sits at the top of the HPG axis, gating GnRH release and downstream sex-steroid production. While its mechanism is endocrine rather than directly central-arousal, it is studied extensively in reproductive-function research and belongs in this category.

Can PT-141 and Kisspeptin-10 be used together in research? They target completely different pathways (central melanocortin signalling vs. hypothalamic GnRH gating), so they can be combined in research designs interrogating both arms of sexual physiology.

What is the half-life of Kisspeptin-10? Reported plasma half-life is short — approximately 4 minutes in human pharmacokinetic studies — which is why infusion or repeat-bolus protocols are common in published research.

Do you ship libido peptides across Canada? Yes — PT-141 and Kisspeptin-10 ship tracked from within Canada via Canada Post or courier, typically arriving in 2–5 business days.

Why does PT-141 sometimes cause flushing or transient blood-pressure changes in published research? MC1 receptors are expressed on vascular endothelium, and broader melanocortin signalling can transiently influence sympathetic tone. These effects are characterized in the published literature and are part of why MC4-selective successors are an active development target.

Compliance

For laboratory research purposes only — not for human consumption. Not approved by Health Canada for therapeutic use.

Internal Links Plan

  1. /products/pt-141-10mg → product page
  2. /products/kisspeptin-10-5mg → product page
  3. /categories/tanning-peptides → cross-category (melanocortin overlap)
  4. /learn/melanocortin-receptor-family → learning hub
  5. /learn/hpg-axis-explained → learning hub
  6. /learn/peptide-reconstitution-guide → learning hub
  7. /learn/bacteriostatic-water-explained → learning hub
  8. /faq/research-use-only-framework → policy page