Melanotan 2 5mg — Vial Spec, Reconstitution Math & COA

Melanotan 2 5mg Vial Overview and Research Application Context

A 5mg vial of Melanotan 2 contains five milligrams of high-purity, lyophilized synthetic peptide, synthesized as a cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). In controlled laboratory environments, the 5mg fill size serves as an ideal baseline quantity for primary assay development, dose-response calibration, and short-term cell culture studies. Researchers working with localized tissue cultures or microfluidic assays often select a 5mg mass standard to minimize unnecessary freeze-thaw degradation cycles associated with larger bulk containers.

Melanotan 2 operates as a non-selective melanocortin receptor agonist. Preclinical investigations evaluate its binding affinity across multiple melanocortin receptor subtypes, primarily MC1R, MC3R, MC4R, and MC5R. The 5mg single-vial format allows investigators to prepare target working stock concentrations without committing excessive material to long-term aqueous storage, ensuring that receptor-binding assays maintain maximal compound integrity over experimental timelines.

Because benchtop parameters demand strict volumetric accuracy, utilizing a 5mg lyophilized cake requires precise solvent calculations. Whether measuring receptor activation kinetics or pigmentary signaling pathway stimulation in keratinocyte-melanocyte co-cultures, starting with a known 5mg mass standard provides an established baseline for accurate molarity determination.

PX1 Catalog Availability: 5mg vs. 10mg Formulations

In institutional procurement, choosing the appropriate vial mass depends on experimental volume, throughput requirements, and storage capabilities. While the 5mg concentration remains a recognized standard for exploratory pilot studies, high-throughput screening environments often utilize larger mass fills to streamline workflow setup and maintain batch uniformity across extended testing runs.

To support scalable research protocols, PX1 Research provides high-purity, lot-tested options across our catalog. If your testing facility requires larger single-vial yields for extended microplate runs, you can review our flagship Melanotan 2 10mg specification, which delivers identical structural purity at double the unit mass. For a broader overview of all available melanocortin agonists and reference standards, explore our complete directory of all research peptides.

Whether operating with 5mg analytical specs or scaled 10mg formats, PX1 Research maintains uniform manufacturing standards across every batch. All lyophilized products undergo identical freeze-drying conditions, ensuring rapid dissolution kinetics and consistent cake structure regardless of total vial volume.

Melanocortin Receptor Signaling and Molecular Mechanism

Melanotan 2 is structurally defined as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. It represents a truncated, lactam-bridged cyclic analog of natural α-MSH. This cyclic conformation significantly enhances enzymatic stability against serum endopeptidases compared to endogenous linear peptides. Preclinical studies suggest that this structural rigidity increases binding affinity and functional potency at central and peripheral melanocortin receptors.

In vitro data indicate that engagement with the MC1R subtype triggers intracellular cyclic adenosine monophosphate (cAMP) accumulation through G-protein coupled receptor (GPCR) activation. This cascade upregulates microphthalmia-associated transcription factor (MITF), subsequently increasing the expression of tyrosinase and related melanogenic enzymes. Researchers investigate these melanocortin activity pathways to analyze skin pigmentation responses, cellular repair mechanisms, and barrier function dynamics under controlled UV radiation models.

Beyond MC1R activity, MT-2 displays potent activity at MC3R and MC4R pathways within central nervous system tissue preparations. Animal study models utilize MT-2 to study metabolic homeostasis, energy expenditure, and central signaling networks governing appetite and vascular dynamics. The non-selective agonist profile makes MT-2 a valuable pharmacological tool for dissecting multi-receptor signaling cascades in comparative tissue models.

Detailed Reconstitution Math: 1 mL, 2 mL, and 3 mL Dilutions

Accurate reconstitution of a 5mg lyophilized vial requires matching the added diluent volume to the target concentration needed for serial dilutions or microplate loading. For most cell culture and biochemical protocols, sterile Bacteriostatic Water (0.9% benzyl alcohol) or sterile normal saline (0.9% NaCl) is used as the primary diluent. Below are the exact concentration yields for a 5mg Melanotan 2 vial using common reconstitution volumes:

1.0 mL Diluent Addition: Adding 1.0 mL of diluent to 5 mg of active peptide yields a final concentration of 5.0 mg/mL (equivalent to 5,000 µg/mL or 5 µg per microliter). This high-density stock is ideal for low-volume microtitration or creating concentrated master stock solutions.

2.0 mL Diluent Addition: Adding 2.0 mL of diluent to 5 mg of active peptide yields a concentration of 2.5 mg/mL (equivalent to 2,500 µg/mL or 2.5 µg per microliter). This intermediate concentration provides a balanced working stock for standard bench top pipetting without requiring sub-microliter adjustments.

3.0 mL Diluent Addition: Adding 3.0 mL of diluent to 5 mg of active peptide yields a concentration of 1.67 mg/mL (equivalent to 1,666.7 µg/mL or ~1.67 µg per microliter). This lower concentration is frequently selected when broader volumetric pipetting is preferred to reduce volumetric error in larger culture wells.

To quickly recalculate concentrations across varying liquid volumes, customized target mass units, or alternative fill sizes, researchers can utilize the PX1 interactive reconstitution calculator for precise bench calculations.

Aliquot Planning and In Vitro Sample Preparation

Repeated freeze-thaw cycles subject peptide chains to physical shear stress and temperature-induced conformational changes, leading to aggregation or peptide cleavage. To preserve the analytical integrity of Melanotan 2 following reconstitution, laboratory technicians should implement an immediate aliquoting protocol.

Upon full dissolution of the 5mg cake—achieved by gently swirling the vial without vigorous shaking—the liquid stock should be divided into single-use microcentrifuge tubes (e.g., polypropylene low-binding tubes). Aliquot volumes should align directly with daily assay consumption parameters (such as 50 µL or 100 µL working volumes).

Working aliquots intended for immediate use within 48 to 72 hours should be stored at 2°C to 8°C, protected from light exposure. Aliquots reserved for future experimental phases must be flash-frozen and stored at -20°C or -80°C. Maintaining dedicated single-use aliquots prevents cross-contamination and ensures uniform concentration standards throughout multi-week study schedules.

Comparative Analysis: Melanotan II, Melanotan I, and PT-141

When designing melanocortin receptor research, selecting the optimal ligand depends heavily on receptor subtype selectivity and half-life characteristics. Melanotan II is often evaluated alongside related analogs such as Melanotan 1 (Afamelanotide) and PT-141 (Bremelanotide) to contrast structural potency and physiological signaling pathways.

Melanotan I is a linear peptide derivative that exhibits high selectivity for the MC1R subtype, making it a primary control standard for isolated melanogenesis studies where central MC3R/MC4R activation is unwanted. Conversely, Melanotan II features a cyclic structure that significantly increases its lipophilicity, receptor binding affinity, and metabolic stability across central and peripheral tissue models.

PT-141 (Bremelanotide) is a synthetic derivative of Melanotan II structurally modified (a hydroxylated metabolite structure) to focus activity on central MC3R and MC4R pathways while exhibiting reduced MC1R activity compared to MT-2. While MT-2 provides broad-spectrum agonist activity across both peripheral pigmentary and central metabolic pathways, PT-141 serves primarily as a target-specific probe for central nervous system signaling research.

Analytical Quality Control: HPLC, MS, and Endotoxin Testing

In vitro and preclinical research requires compounds of verified purity to prevent experimental anomalies caused by truncated peptide fragments, residual reagents, or microbial endotoxins. PX1 Research subjects every batch of Melanotan 2 to rigorous analytical verification performed in ISO 17025 accredited third-party laboratories within the USA.

Purity is quantified using High-Performance Liquid Chromatography (HPLC), confirming that every lot meets or exceeds a baseline threshold of 98.0% chemical purity. Mass Spectrometry (MS) analysis is performed simultaneously to verify exact molecular weight (1024.2 g/mol) and sequence identity, ensuring freedom from baseline structural isomers or synthase artifacts.

Biological assays, particularly those involving sensitive cell lines or tissue explants, are highly vulnerable to lipopolysaccharide contamination. PX1 performs Limulus Amebocyte Lysate (LAL) testing on every lot to guarantee endotoxin levels remain strictly below standard safety thresholds (<0.01 EU/µg). Researchers can access batch-specific documentation directly via our verified Certificate of Analysis portal.

Storage, Stability, and Handling Protocols

Lyophilized Melanotan 2 5mg vials must be stored under temperature-controlled conditions to prevent humidity degradation and thermal peptide cleavage. Upon arrival at the laboratory facility, un-reconstituted vials should be kept in a desiccated freezer environment at -20°C for long-term storage (up to 24 months) or at 2°C to 8°C for short-term storage (up to 90 days).

Vials should be allowed to equilibrate to room temperature prior to reconstitution. Introducing cold diluent into a cold vacuum vial can induce moisture condensation inside the container, potentially compromising peptide stability. Reconstitution should be performed under a laminar flow hood using aseptic technique.

Reconstituted solutions must be protected from direct light exposure using amber vials or foil wrappings. Aqueous MT-2 exposed to room light and ambient temperatures demonstrates accelerated chemical degradation, leading to altered binding kinetics in sensitive receptor assays.

Sourcing Standards for Preclinical Research Design

Selecting a reliable supplier for research-grade peptides is critical for data reproducibility across experimental replicates. PX1 Research manufactures all compounds in GMP-compliant facilities within the USA, avoiding non-standardized overseas Sourcing risks and ensuring continuous quality control from synthesis through fill-finish operations.

Orders ship directly from our centralized distribution facilities in California and Arizona, offering same-day dispatch for orders finalized Monday through Friday before cut-off times. This rapid fulfillment chain minimizes transit time and prevents exposure to extreme ambient temperature fluctuations during transport.

For institutional laboratories establishing multi-phase research protocols, access to comprehensive documentation and reliable supply volume is paramount. Explore our broader clinical research catalog via the central PX1 Research hub or review volume procurement options through our dedicated wholesale laboratory program.