What Is PT-141 (Bremelanotide)?
PT-141, known by its International Nonproprietary Name (INN) bremelanotide, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH). It was originally derived from the melanocortin peptide Melanotan II during research into its physiological properties. PT-141 acts as a non-selective agonist at melanocortin receptors (MCRs), with documented activity at MC1R, MC3R, MC4R, and MC5R subtypes.
In the United States, bremelanotide received FDA approval under the brand name Vyleesi for a specific clinical indication. In Canada, PT-141 is not approved by Health Canada for any therapeutic application. TrueCanPeptides supplies research-grade PT-141 for qualified preclinical and laboratory research use only, strictly within the parameters of applicable Canadian regulatory frameworks.
Mechanism of Action — Research Context
PT-141’s primary pharmacological profile centres on its activity at melanocortin receptors in the central nervous system. The MC4R subtype, expressed in hypothalamic regions including the paraventricular nucleus, has been a focus of preclinical research in relation to CNS regulatory circuits studied in behavioural neuroscience.
Unlike compounds that act primarily through peripheral vascular mechanisms, PT-141’s research profile has been characterised by investigators as CNS-mediated, with preclinical studies examining signal transduction through cAMP-dependent pathways following melanocortin receptor activation. All mechanistic descriptions here are derived from the preclinical and early-phase clinical research literature.
Research Applications
- Melanocortin receptor pharmacology: PT-141 is used as a tool compound in studies examining MC3R and MC4R biology, receptor binding kinetics, and downstream signalling in cell culture and animal models.
- Behavioural neuroscience: Preclinical studies have used PT-141 to investigate hypothalamic circuitry and the role of melanocortin signalling in behavioural paradigms in rodent models.
- Neuroendocrine research: The melanocortin system intersects with multiple neuroendocrine axes, making PT-141 a relevant tool in studies examining central regulatory mechanisms.
- Melanocyte biology: As an α-MSH analogue, PT-141 has also been studied in dermatological research contexts examining pigmentation pathways through MC1R.
- Peptide structural research: The cyclic structure of PT-141 makes it a useful reference compound in structure-activity relationship (SAR) studies of melanocortin analogues.
All research use of PT-141 must comply with applicable institutional review processes, ethical guidelines, and Canadian regulatory requirements. This compound is supplied for laboratory and preclinical research applications only.
View PT-141 10mg — Research Grade
Storage & Handling
PT-141 is a cyclic peptide with generally good stability relative to linear peptides, but standard laboratory handling protocols should be followed:
- Store lyophilised powder at −20°C in sealed containers away from light and moisture
- Reconstitute with sterile bacteriostatic water or appropriate aqueous solvent per your laboratory SOP
- Store reconstituted peptide at 4°C and use within the timeframe specified by your protocol
- Avoid freeze-thaw cycling; aliquot single-use volumes where feasible
Review our Peptide Storage Guide and Quality & Purity standards for additional information.
Related Research
PT-141 is part of the melanocortin analogue research space, which includes α-MSH, Melanotan I, Melanotan II, and various synthetic analogues developed to study receptor selectivity and downstream pathway biology. Researchers examining peptide CNS biology may find relevant context in the broader neuropeptide and neuroendocrine literature. Melanocortin receptor subtype pharmacology is a well-established research field with extensive published literature covering both central and peripheral receptor functions.
Browse the Research Hub for more compound overviews. Review What Are Peptides? and our Quality & Purity standards to understand how we ensure research-grade integrity.
⚠️ Research Use Only: All content on this page is intended strictly for educational and informational purposes. This compound is not approved by Health Canada or any regulatory agency for human therapeutic use. TrueCanPeptides supplies research-grade compounds to qualified researchers only. This is not medical advice. Do not use any information here for self-administration, diagnosis, or treatment. Consult a licensed healthcare professional for any medical concerns.
See also: What is Kisspeptin?
PT-141 (Bremelanotide): Melanocortin Research Background
PT-141 (bremelanotide) is a cyclic heptapeptide derived from Melanotan 2 (MT-2). It was identified during MT-2 research when the N-terminal acetyl group was removed and the peptide was cyclized via a lactam bridge — producing a compound with similar melanocortin receptor affinity but different physicochemical and pharmacokinetic properties. PT-141 was subsequently developed by Palatin Technologies into an approved pharmaceutical product (Vyleesi — intranasal formulation) for hypoactive sexual desire disorder (HSDD) in premenopausal women, making it one of the few peptides in this catalog with an approved drug counterpart.
Structure and Chemistry
- Systematic name: cyclo[β-Ala-His-D-Phe-Arg-Trp-Glu]-Lys-OH (cyclic heptapeptide)
- Amino acids: 7 (cyclic)
- Molecular weight: ~1,025 Da
- Receptor targets: MC1R, MC3R, MC4R, MC5R — same melanocortin receptor family as MT-2
- Key difference from MT-2: Deacetylated; different cyclization; slower melanocortin receptor dissociation in some models
- Format: Lyophilized powder
Central Melanocortin Research Context
PT-141’s pharmacological profile is characterized by significant central nervous system activity via MC3R and MC4R — melanocortin receptors expressed in hypothalamic and limbic brain regions. MC4R activation in the hypothalamus is associated with neuronal circuits governing sexual behaviour and arousal in preclinical models, and this is the basis for both its research interest and its clinical development pathway.
Research using PT-141 as a pharmacological tool has contributed to understanding of central melanocortin circuit biology, the role of MC4R in reward and sexual motivation signalling, and the interaction between melanocortin and dopaminergic pathways. These mechanistic research questions remain active areas of investigation.
PT-141 vs MT-2: Key Research Differences
| Property | PT-141 (Bremelanotide) | Melanotan 2 (MT-2) |
|---|---|---|
| MW | ~1,025 Da | ~1,024 Da |
| N-terminus | Free (deacetylated) | Acetylated |
| Cyclization | Lactam (Glu-Lys) | Lactam (Asp-Lys) |
| Approved drug | Yes — Vyleesi (FDA, 2019) | No |
| Primary research context | Central MC4R, sexual behaviour circuits | Melanocortin receptor pharmacology |
Storage and Handling
- Store lyophilized at −20°C; protect from light (contains Trp and His residues)
- Reconstitute in sterile water; water-soluble
- Post-reconstitution: 4°C up to 7 days; aliquot and freeze at −20°C for longer storage
PT-141 is supplied for qualified in vitro laboratory research purposes only. Not for human or animal administration. Not evaluated or approved by Health Canada.
Available: PT-141 from TrueCanPeptides | Melanotan 2 guide | Cognitive & Neuro research compounds