Original bremelanotide PT 141 is a synthetic cyclic heptapeptide investigated extensively for its role as a selective melanocortin receptor agonist. Designed specifically for laboratory research use, this peptide serves as a primary reference compound for evaluating central nervous system pathways that govern neuroendocrine signaling and behavioral responses.
Original bremelanotide PT 141 is a synthetic cyclic heptapeptide investigated extensively for its role as a selective melanocortin receptor agonist. Designed specifically for laboratory research use, this peptide serves as a primary reference compound for evaluating central nervous system pathways that govern neuroendocrine signaling and behavioral responses.
Original bremelanotide PT 141 is a synthetic cyclic heptapeptide analog of naturally occurring alpha-melanocyte-stimulating hormone (α-MSH). Chemically designated as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, it possesses a molecular weight of approximately 1024.18 g/mol. Unlike linear peptide chains, its cyclic structure is conferred by a lactam bridge between the side chains of the aspartic acid and lysine residues. This conformational constraint significantly enhances enzymatic stability against serum peptidases, making it an ideal candidate for rigorous in vitro and preclinical research protocols.
Originally derived as a metabolite of the skin-pigmentation research compound Melanotan II, PT 141 was observed to exhibit distinct receptor selectivity profiles. By removing the C-terminal amide structure present in earlier analogs, researchers isolated a peptide compound that preferentially engages central melanocortin receptors rather than driving peripheral melanogenesis. In pure research settings, obtaining verified PT-141 Bremelanotide reference material ensures batch-to-batch consistency required for accurate receptor binding studies.
The primary mechanism of action for original bremelanotide PT 141 involves high-affinity binding to specific members of the melanocortin receptor family—a class of five distinct G-protein-coupled receptors (GPCRs) designated MC1R through MC5R. Pharmacological profiling indicates that PT 141 acts predominantly as an agonist at the MC3R and MC4R sub-types, with secondary affinity for MC1R and minimal interaction at MC2R and MC5R.
Upon binding to central MC3R and MC4R sub-types, bremelanotide activates the stimulatory G-protein (Gαs) pathway, triggering adenylate cyclase activation and a subsequent rise in intracellular cyclic adenosine monophosphate (cAMP) levels. This intracellular cascade downstream modulates specific central nervous system circuits, particularly within the medial preoptic area (mPOA), paraventricular nucleus (PVN), and hypothalamus. Researchers investigating melanocortin receptor agonists utilize this specific pathway to map central control of neuroendocrine and behavioral signaling independently of vascular or peripheral enzymatic drivers.
In preclinical animal models, original bremelanotide PT 141 has been widely evaluated to decipher the central mechanisms regulating appetitive and consummatory behaviors. Rodent studies published in peer-reviewed neurobiology literature demonstrate that central administration of PT 141 stimulates specific hypothalamic nuclei, initiating downstream dopaminergic transmission in the mesolimbic pathway.
Unlike traditional vasoactive compounds that alter peripheral hemodynamics via nitric oxide pathways, PT 141 operates entirely within the central nervous system. Preclinical assays demonstrate that activation of MC4R by PT 141 facilitates neural firing in the mPOA, modulating autonomic output without inducing direct structural changes in peripheral vasculature. Data gathered from rodent models highlight its utility as a chemical probe to study central motivation, neuroendocrine regulation, and autonomic reflex arcs in controlled laboratory environments. Comprehensive findings across various models can be explored further in the PX1 Research library.
Understanding the distinct pharmacological profile of bremelanotide requires evaluating its activity alongside structurally related peptides in the melanocortin class. While native peptides and early synthetic derivatives offer valuable baseline data, sequence modifications create substantial variations in receptor affinity and metabolic half-life.
When comparing PT-141 against Melanotan II and Afamelanotide, clear functional differences emerge. Melanotan II demonstrates non-selective activation across MC1R, MC3R, MC4R, and MC5R, frequently resulting in potent peripheral melanogenesis due to strong MC1R binding. In contrast, PT-141 exhibits a modified structure that reduces relative MC1R potency while preserving high affinity for central MC3R and MC4R pathways, limiting pigmentary activity in experimental settings. Similarly, while endogenous Alpha-MSH undergoes rapid enzymatic degradation in vitro within minutes, the lactam-bridged cyclic framework of original bremelanotide provides marked resistance to proteolysis, allowing sustained receptor engagement during extended cellular assays.
Quantitative evaluation of original bremelanotide PT 141 relies on standardized in vitro binding and functional assays. Receptor affinity is typically measured using radioligand displacement assays on cell lines stably expressing human recombinant MC3R or MC4R receptors (such as HEK293 or CHO cells). In these models, PT 141 demonstrates equilibrium inhibition constants (Ki values) in the nanomolar range.
Functional potency is quantified by measuring cAMP accumulation following peptide exposure. Investigators establish dose-response curves to calculate half-maximal effective concentrations (EC50). Achieving precise, reproducible EC50 values requires ultra-pure peptide reagents free from truncated fragments or residual trifluoroacetate (TFA) salts, as chemical impurities can falsely shift binding kinetics or cause non-specific cytotoxic responses in cell cultures.
To maintain structural integrity and prevent premature hydrolysis, lyophilized original bremelanotide PT 141 must be stored under controlled thermal conditions upon receipt. Unopened vials containing lyophilized powder should be stored at -20°C for short-term preservation or -80°C for long-term stability. The dry powder matrix remains stable under these conditions when kept away from moisture and ambient light.
When preparing the compound for in vitro or experimental protocols, reconstitution should be performed using laboratory-grade solvents such as sterile bacteriostatic water or sterile 0.9% sodium chloride solution. Solvent should be introduced slowly down the inner wall of the glass vial, allowing the lyophilized cake to dissolve naturally without violent vortexing, which can induce physical shear stress and peptide aggregation. Once reconstituted, liquid solutions should be aliquoted into single-use microcentrifuge tubes to prevent repeated freeze-thaw cycles and stored at 4°C for short-term usage (up to 7 days) or -20°C for extended experimental timelines. Researchers requiring volume-specific dilution tables can refer to our peptide reconstitution calculator.
Reliable scientific data requires standard-grade reference peptides verified through rigorous analytical chemistry techniques. Primary verification of original bremelanotide PT 141 involves Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) to establish chemical purity. High-grade research material should exhibit a single sharp chromatographic peak corresponding to a purity level of ≥98.0%, confirming the absence of synthesized deletion sequences or unreacted reagents.
Identity verification is conducted via Electrospray Ionization Mass Spectrometry (ESI-MS) or Matrix-Assisted Laser Desorption/Ionization (MALDI-TOF), confirming the precise monoisotopic mass of 1024.18 Da. Additionally, because bacterial endotoxins (lipopolysaccharides) can bind to cell membrane receptors and trigger confounding inflammatory cascades in vitro, research-grade PT 141 must undergo chromogenic Limulus Amebocyte Lysate (LAL) testing to confirm endotoxin levels remain strictly below <0.1 EU/mg.
PX1 Research supplies high-purity original bremelanotide PT 141 strictly intended for laboratory research use and in vitro experimentation. Every lot produced undergoes synthesis within cGMP-compliant facilities and undergoes independent verification by an accredited ISO 17025 laboratory located within the United States. This rigorous quality pipeline guarantees that every vial meets strict specifications for identity, purity, and freedom from heavy metals or endotoxins.
Researchers sourcing reagents from PX1 Research receive lot-specific Certificates of Analysis (COAs) containing full RP-HPLC chromatograms and mass spectra. Orders ship directly from state-of-the-art fulfillment centers located in California and Arizona, with same-day dispatch available Monday through Friday. Academic, corporate, and government research laboratories needing ongoing reagent supply can manage bulk procurement through PX1 wholesale accounts.
Beyond its established role in mapping central behavioral pathways, original bremelanotide PT 141 remains an active focal point in broader neuroendocrine research. Emerging studies investigate how central MC3R and MC4R activation interacts with metabolic regulation, systemic energy balance, and neuroinflammatory cascades within the central nervous system.
By utilizing highly pure, chemically characterized melanocortin agonists, investigators can systematically map signal transduction across various brain regions. As research progresses into the cross-talk between melanocortinergic pathways and other neuropeptide networks, original bremelanotide PT 141 remains a essential reference tool for molecular pharmacology and neurobiology laboratories worldwide.
What is original bremelanotide PT 141 used for in a laboratory setting?
Original bremelanotide PT 141 is used as a synthetic reference compound to study melanocortin receptor pharmacology, specifically target binding, cAMP signal transduction, and neuroendocrine behavioral pathways in cell cultures and animal models.
How does PT 141 differ structurally from native alpha-MSH?
PT 141 is a cyclic heptapeptide analog featuring a lactam bridge, whereas native alpha-MSH is a linear 13-amino acid peptide. This cyclic structure significantly increases chemical stability and enzymatic resistance in vitro.
Which melanocortin receptors does original bremelanotide target?
Preclinical binding studies indicate that bremelanotide PT 141 acts primarily as a high-affinity agonist at MC3R and MC4R sub-types, with secondary affinity at MC1R.
What analytical testing is performed on PX1 Research PT 141?
Every lot undergoes RP-HPLC to verify chemical purity (≥98%), mass spectrometry (ESI-MS or MALDI-TOF) to confirm molecular weight (1024.18 Da), and LAL testing to ensure endotoxin levels are below 0.1 EU/mg.
What solvent should be used to reconstitute lyophilized PT 141 for laboratory use?
Lyophilized PT 141 is typically reconstituted using sterile bacteriostatic water or sterile 0.9% sodium chloride solution depending on the specific requirements of the in vitro or experimental protocol.
How should reconstituted PT 141 solutions be stored?
Reconstituted liquid solutions should be aliquoted into single-use tubes to avoid freeze-thaw cycles and stored at 4°C for short-term use (up to 7 days) or -20°C for long-term experimental storage.
Is original bremelanotide PT 141 approved for human consumption or clinical use?
No. The compound supplied by PX1 Research is provided strictly as a laboratory research chemical for in vitro and preclinical experimentation. It is not for human or veterinary use.
Where does PX1 Research manufacture and ship its research peptides?
All PX1 Research peptides are manufactured in USA-based cGMP-compliant facilities and shipped directly from distribution centers in California and Arizona with same-day shipping available Monday through Friday.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.