PX1 Research provides reference-standard melanocyte-stimulating hormone (MSH) peptides for qualified academic, institutional, and enterprise laboratories. Every lot undergoes rigorous third-party analytical testing, including RP-HPLC purity verification and mass spectrometry characterization, ensuring strict reproducibility for in vitro and preclinical research applications.
PX1 Research provides reference-standard melanocyte-stimulating hormone (MSH) peptides for qualified academic, institutional, and enterprise laboratories. Every lot undergoes rigorous third-party analytical testing, including RP-HPLC purity verification and mass spectrometry characterization, ensuring strict reproducibility for in vitro and preclinical research applications.
Qualified institutions seeking high-purity melanocyte-stimulating hormone for sale require analytical certainty, batch-to-batch consistency, and fully transparent documentation. PX1 Research supplies laboratory-grade MSH peptides manufactured in GMP-compliant, USA-based facilities. Every batch includes a lot-specific Certificate of Analysis (COA) detailing identity verification via mass spectrometry, purity determination exceeding 99% via High-Performance Liquid Chromatography (HPLC), and quantitative bacterial endotoxin testing.
When purchasing endogenous or synthetic MSH variants for experimental assays, sourcing verified reference standards is essential to eliminate biochemical artifacts caused by truncated peptide sequences, residual TFA salts, or endotoxin contamination. PX1 Research ships directly from fulfillment centers in California and Arizona with same-day dispatch for orders placed Monday through Friday, supporting rigorous investigative timelines for researchers nationwide.
Melanocyte-stimulating hormones represent a class of peptide hormones belonging to the melanocortin family, derived from the post-translational pro-opiomelanocortin (POMC) precursor pro-protein. Enzymatic cleavage of POMC by prohormone convertases yields three principal endogenous MSH isoforms: alpha-MSH (α-MSH), beta-MSH (β-MSH), and gamma-MSH (γ-MSH). Among these, α-MSH is the most thoroughly characterized in preclinical literature.
Structurally, α-MSH is a 13-amino-acid tridecapeptide carrying an N-terminal acetyl group and a C-terminal carboxamide group (Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2). This structural configuration confers enzymatic stability against specific aminopeptidases. In vitro assays demonstrate that the conserved pharmacophore sequence—His-Phe-Arg-Trp—is directly responsible for receptor binding and activation across the melanocortin receptor (MCR) family. Investigators analyzing receptor kinetics often utilize synthesized variants available through our all-peptides catalog to examine binding affinity differences between natural isoforms and stabilized analogues.
The physiological and cellular effects of MSH peptides are mediated via five distinct G-protein-coupled receptor (GPCR) subtypes designated MC1R through MC5R. Binding of MSH to these receptors activates the heterotrimeric Gs protein subunit, stimulating intracellular adenylyl cyclase activity and raising intracellular cyclic adenosine monophosphate (cAMP) concentrations.
Downstream of cAMP accumulation, protein kinase A (PKA) phosphorylates the cAMP response element-binding protein (CREB). In melanocytes, CREB transcriptionally upregulates Microphthalmia-associated Transcription Factor (MITF), which drives the expression of key melanogenic enzymes including tyrosinase, tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT).
Preclinical data indicate that target selectivity varies significantly across receptor subtypes. MC1R is predominantly expressed in cutaneous melanocytes and immune cells; MC2R serves as the specific receptor for adrenocorticotropic hormone (ACTH); MC3R and MC4R are centrally expressed in the hypothalamus and brainstem; and MC5R is widely expressed in exocrine glands. Detailed mapping of these pathways can be found in our comprehensive alpha-MSH signaling mechanisms documentation in the PX1 research library.
In vitro models using primary human melanocytes and B16 melanoma cell lines have demonstrated that α-MSH stimulation significantly elevates basal tyrosinase activity and shifts melanin synthesis from the reddish-yellow pheomelanin pathway toward the dark brown-black eumelanin pathway. Eumelanin exhibits superior physical ultraviolet (UV) light absorption and free radical scavenging capabilities relative to pheomelanin.
Rodent models examining photoprotective responses suggest that MSH signaling enhances nucleotide excision repair (NER) pathways following exposure to ultraviolet radiation. By accelerating the removal of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts in DNA, MSH receptor activation reduces genomic instability resulting from oxidative stress. Furthermore, in vitro studies reveal that α-MSH suppresses pro-inflammatory cytokines such as TNF-alpha, IL-1 alpha, and IL-6 in keratinocytes, demonstrating a dual role in pigmentary modulation and localized anti-inflammatory responses.
Beyond cutaneous melanocytes, central administration of MSH peptides in animal models highlights a fundamental role in hypothalamic metabolic control. Neurons within the arcuate nucleus of the hypothalamus synthesize POMC, releasing α-MSH to target MC3R and MC4R expressed in the paraventricular nucleus and lateral hypothalamic area.
Preclinical studies suggest that central MC4R activation by MSH acts as a primary anorexigenic signal, suppressing food intake and increasing energy expenditure via sympathetic nervous system activation of brown adipose tissue thermogenesis. Knockout rodent models lacking functional MC4R consistently exhibit severe hyperphagia and metabolic dysfunction, establishing the MSH-MC4R axis as a primary focal point for obesity and metabolic syndrome research.
Endogenous α-MSH exhibits a short circulating half-life in biological matrices due to rapid enzymatic degradation by neutral endopeptidases and prolyl endopeptidases. To facilitate extended in vitro and in vivo studies, medicinal chemists engineered synthetic analogues with modified amino acid sequences, such as D-phenylalanine substitutions and cyclic lactam backbones.
When evaluating compounds within the melanocortin class, laboratories often compare native α-MSH against synthetic derivatives. For instance, Melanotan 1 (Afamelanotide) is a linear peptide analogue featuring N-leucine and D-phenylalanine modifications that enhance MC1R potency and enzymatic resistance. Similarly, Melanotan 2 incorporates a cyclic structure that broadens receptor binding across MC1R, MC3R, MC4R, and MC5R. Another widely researched derivative, PT-141 (Bremelanotide), is a metabolite derivative tailored specifically toward central MC3R and MC4R pathways. Comparing these peptides within identical cell culture models provides valuable data regarding receptor subtype selectivity and structural stability.
Melanocyte-stimulating hormone peptides are supplied by PX1 Research as lyophilized (freeze-dried) cakes or powders in sterile glass vials. Proper handling requires strict adherence to aseptic laboratory procedures to avoid biological or chemical contamination.
Before reconstitution, vials should be allowed to equilibrate to room temperature to minimize condensation inside the container. Reconstitution is typically performed using Bacteriostatic Water (0.9% benzyl alcohol preserved) for multi-use assay sampling or sterile Reconstitution Grade Water / 0.9% Sodium Chloride Injection for immediate cell culture applications. Solvents should be introduced slowly down the inner glass wall of the vial, followed by gentle swirling. Never shake the vial, as vigorous agitation can induce shear stress and cause peptide denaturation or aggregation. For step-by-step guidance on solvent compatibility and concentration calculations, researchers can consult our detailed peptide storage and reconstitution guide.
Lyophilized MSH peptides possess high thermal stability when stored dry at -20°C or -80°C, protected from light exposure. Under these conditions, the unconstituted peptide maintains chemical integrity and full biological potency for up to 24 months.
Once reconstituted into aqueous solution, peptide stability decreases significantly. Reconstituted aliquots should be stored at 2°C to 8°C and evaluated within short experimental timeframes (typically 14 to 30 days depending on the reconstitution medium used). For long-term liquid storage, reconstitate at working concentrations using buffer solutions with protein stabilizers (such as 0.1% BSA), split into single-use aliquots, and freeze at -80°C to eliminate repeated freeze-thaw cycles. Repeated thermal cycling causes peptide cleavage and aggregation, compromising experimental accuracy.
Acquiring high-purity melanocyte-stimulating hormone for sale requires verification of analytical standards. Substandard research compounds containing synthesis impurities, side-chain protecting group remnants, or bacterial endotoxins yield inconsistent experimental assays and cellular toxicity.
PX1 Research maintains an uncompromising quality assurance framework for every lot of MSH produced:
1. Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC): Establishes chromatographic purity, ensuring the target MSH peak represents >99% of total integrated UV area at 214nm and 280nm.
2. Electrospray Ionization Mass Spectrometry (ESI-MS) or MALDI-TOF: Confirms exact molecular weight and amino acid sequence identity against theoretical mass.
3. Bacterial Endotoxin Testing (LAL Assay): Verifies that endotoxin levels remain below stringent thresholds (<0.05 EU/mg), eliminating false-positive inflammatory responses in cell culture models.
4. Domestic USA Manufacturing: Produced in state-of-the-art ISO 17025 accredited and GMP-compliant facilities operating within the United States.
Every product page includes direct access to verifiable, lot-specific COA documents, giving researchers total confidence in compound integrity.
Principal investigators, CROs, and institutional procurement departments requiring custom peptide synthesis, specific salt formulations (e.g., acetate vs. TFA-free), or high-volume orders can leverage our specialized infrastructure.
Through our dedicated wholesale program, PX1 Research provides custom batch sizes, tailored vial configurations, and volume-tiered institutional pricing while maintaining batch-level analytical transparency and same-day CA/AZ shipping services.
What is the purity standard for MSH peptides available at PX1 Research?
PX1 Research guarantees a minimum analytical purity of 99% for melanocyte-stimulating hormone research compounds, as measured by High-Performance Liquid Chromatography (HPLC) and verified by mass spectrometry.
Is melanocyte-stimulating hormone available for human administration?
No. All products offered by PX1 Research, including MSH peptides, are strictly intended for laboratory research, in vitro studies, and preclinical scientific investigation. They are not for human or veterinary consumption, therapy, or clinical use.
What documentation accompanies an MSH peptide shipment?
Each lot of MSH peptide is supplied with a lot-specific Certificate of Analysis (COA) detailing RP-HPLC purity charts, mass spectrometry identification spectra, mass balance, and bacterial endotoxin test results.
How should lyophilized MSH be stored upon receipt?
Lyophilized MSH should be stored in a freezer at -20°C or -80°C upon arrival, protected from light and moisture. Stored desiccated at these temperatures, the peptide remains stable for up to 24 months.
What liquid reconstituted solutions are recommended for MSH assays?
For standard laboratory assays, MSH is typically reconstituted using sterile Bacteriostatic Water or sterile 0.9% Sodium Chloride. For cell culture experiments sensitive to preservatives, sterile endotoxin-free water or PBS buffer is recommended.
Why is endotoxin testing critical when purchasing MSH for research?
Bacterial endotoxins (lipopolysaccharides) stimulate immune responses in cell cultures and animal models, triggering inflammatory cascades that mask or distort the true receptor-mediated actions of MSH peptides. PX1 tests every batch to guarantee minimal endotoxin levels (<0.05 EU/mg).
What receptor subtypes does native alpha-MSH target?
Alpha-MSH acts as an agonist across MC1R, MC3R, MC4R, and MC5R, with high affinity for the MC1R receptor found in melanocytes and immune cells.
How quickly does PX1 Research ship MSH orders to research facilities?
PX1 Research dispatches orders same-day for purchases placed Monday through Friday prior to regional cutoffs, shipping directly from facilities in California and Arizona.
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.