In short: PT-141 is a research-grade peptide that functions as a melanocortin receptor agonist, primarily studied for its selective binding affinity to melanocortin-1 receptor (MC1R) and melanocortin-4 receptor (MC4R) pathways in laboratory settings.

Key Takeaways

  • PT-141 is a cyclic heptapeptide (seven amino acids) designed as a selective MC1R/MC4R agonist, manufactured to ≥99% purity and verified via HPLC and mass spectrometry by third-party laboratories.
  • The melanocortin receptor system is a G-protein-coupled receptor (GPCR) signalling pathway involved in multiple physiological processes studied across endocrinology, neuroscience, and dermatology research models.
  • PT-141 research applications focus on melanocortin pathway activation in ex vivo tissue models, cell-based assays, and animal model studies, not human application.
  • Research-grade PT-141 is supplied as lyophilised powder and requires bacteriostatic water for reconstitution to maintain stability during laboratory storage and experimental protocols.
  • MyoLabs PT-141 is accompanied by batch-specific Certificates of Analysis detailing purity, peptide sequence confirmation, and endotoxin levels for scientific reproducibility.

PT-141: Structure and Melanocortin Receptor Binding

PT-141 is a synthetic cyclic peptide engineered to target the melanocortin receptor family, a subfamily of G-protein-coupled receptors (GPCRs) expressed across central and peripheral tissues. In laboratory research, PT-141 is studied for its selective agonist activity at melanocortin-1 receptor (MC1R) and melanocortin-4 receptor (MC4R), two of five known human melanocortin receptor subtypes. Researchers use PT-141 to investigate how melanocortin pathway activation influences downstream cellular signalling cascades, including cyclic adenosine monophosphate (cAMP) accumulation and protein kinase A (PKA) activation in cultured cells and tissue explants.

The melanocortin system is distributed across the hypothalamus, pituitary gland, skin, immune cells, and peripheral tissues, making it a subject of broad research interest. PT-141 allows researchers to selectively activate MC1R and MC4R without concurrent activation of melanocortin-3 receptor (MC3R), melanocortin-2 receptor (MC2R), or melanocortin-5 receptor (MC5R), enabling pathway-specific investigation in controlled laboratory models. As a research compound, PT-141 is typically supplied at ≥99% purity, with purity verification performed using high-performance liquid chromatography (HPLC) and confirmed by mass spectrometry to ensure batch consistency across experimental replicates.

Melanocortin Receptor Signalling Pathways in Research Models

Researchers studying the melanocortin system use PT-141 in several established laboratory paradigms:

  • In vitro cell-based assays: Transfected mammalian cells (typically HEK293 or CHO cell lines) expressing recombinant MC1R or MC4R receptors are exposed to PT-141 at defined concentrations to measure receptor-mediated cAMP production and downstream transcriptional responses.
  • Receptor binding studies: Radioligand competition assays and surface plasmon resonance (SPR) experiments quantify PT-141 binding affinity and selectivity at native and recombinant melanocortin receptors isolated from tissues or cell membranes.
  • Ex vivo tissue models: Skin biopsies and hypothalamic tissue explants are treated with PT-141 to investigate local melanocortin pathway activation and its functional consequences in tissue-specific contexts.
  • Animal model research: Rodent models are used to study whole-organism melanocortin signalling; PT-141 administration allows researchers to observe receptor-mediated effects on defined physiological endpoints under controlled laboratory conditions.

The melanocortin receptor system is notable for its pleiotropic effects across multiple biological systems. Research into PT-141 activity helps clarify the tissue-specific and receptor-subtype-specific consequences of melanocortin pathway activation, contributing to fundamental knowledge of GPCR signalling architecture and ligand-receptor selectivity in mammalian physiology.

Storage, Handling, and Quality Assurance for Research PT-141

PT-141 is supplied by MyoLabs as a lyophilised (freeze-dried) powder that must be reconstituted using bacteriostatic water before use in experiments. Lyophilisation preserves peptide integrity during storage at −20 °C or below; once reconstituted, PT-141 solutions should be stored at 2–8 °C and used within the timeframe specified in the product documentation to maintain biological activity. Researchers should verify that reconstituted PT-141 remains free of particulates and discolouration before inclusion in assays.

Every batch of research-grade PT-141 supplied by MyoLabs includes a batch-specific Certificate of Analysis (COA) documenting HPLC purity (typically ≥99%), peptide sequence verification via mass spectrometry, moisture content, and bacterial endotoxin levels. These analytical reports enable researchers to confirm compound identity and purity before experiments begin, supporting reproducibility across laboratory studies and compliance with research standards. For detailed guidance on interpreting analytical reports, researchers should consult MyoLabs lab reports and the research series on peptide quality verification.

Frequently Asked Questions

What is the difference between PT-141 and other melanocortin agonists used in research?

PT-141 is a selective MC1R/MC4R agonist, whereas other melanocortin agonists (such as α-melanocyte-stimulating hormone, or α-MSH) activate multiple melanocortin receptor subtypes with lower selectivity. PT-141's cyclic structure and synthetic design confer greater receptor selectivity, allowing researchers to isolate MC1R and MC4R signalling without concurrent activation of MC2R, MC3R, or MC5R in laboratory models.

How long does reconstituted PT-141 remain stable for research use?

Reconstituted PT-141 stored at 2–8 °C typically remains suitable for laboratory use for up to 2–4 weeks; however, researchers should verify stability by visual inspection (no particulates or discolouration) and confirm product-specific stability data provided in the Certificate of Analysis before use in time-sensitive experiments.

What analytical methods confirm the purity of research-grade PT-141?

PT-141 purity is verified using high-performance liquid chromatography (HPLC) coupled with ultraviolet detection, and peptide identity is confirmed by liquid chromatography–mass spectrometry (LC-MS) or direct infusion mass spectrometry, with batch-specific results documented in the Certificate of Analysis.

Research Use Only. MyoLabs products are supplied strictly for laboratory research use and are not for human or animal consumption.