Melanotan 2 20mg — Vial Spec, Reconstitution Math & COA

Overview & Vial Specification (20mg Mass)

A 20mg vial of Melanotan 2 (MT-2) contains 20 milligrams of highly purified, lyophilized synthetic cyclic heptapeptide acetate salt. High-throughput screening facilities, automated assay platforms, and multi-animal longitudinal studies frequently require larger mass configurations such as 20mg to prepare standardized master stock solutions without introducing vial-to-vial variance across experimental replicates. Reconstitution of a single 20mg vial provides twice the working volume of standard single-vial packaging, enabling consistent assay conditions across multi-well plate setups or extended animal study protocols.

While 20mg mass units offer operational efficiency for large-scale laboratory screening, PX1 Research primary stocking maintains the individual Melanotan II 10mg vial to optimize physical stability and prevent unnecessary freeze-thaw degradation in standard benchtop environments. Researchers seeking 20mg mass specifications for high-volume pipelines can utilize the reconstitution formulas detailed herein, or coordinate custom bulk fills through our laboratory support team. All Melanotan II formulations supplied by PX1 Research undergo rigorous analytical verification to ensure identical chemical purity, salt stoichiometry, and structural integrity regardless of fill volume.

Molecular Structure & Melanocortin Receptor Binding Profile

Melanotan 2 (CAS 121062-08-6) is a synthetic, cyclic lactam analog of the naturally occurring alpha-melanocyte-stimulating hormone (α-MSH). Chemically designated as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, it features a molecular formula of C50H69N15O9 and a molecular mass of 1024.2 g/mol. The incorporation of a D-phenylalanine residue at position 7 alongside side-chain-to-side-chain cyclization between Asp3 and Lys8 imparts significant enzymatic resistance against endopeptidases, markedly increasing its biological half-life relative to endogenous α-MSH in experimental models.

Preclinical studies suggest that Melanotan 2 acts as a non-selective, potent agonist across multiple central and peripheral melanocortin receptor subtypes. In vitro receptor binding assays demonstrate high affinity for MC1R (which regulates skin pigmentation pathways), MC3R, MC4R (involved in energy homeostasis and central signaling), and MC5R. The broad activity profile makes MT-2 a primary reference standard in cell culture assays examining melanogenesis, intracellular cyclic adenosine monophosphate (cAMP) accumulation, and receptor ligand interactions.

Reconstitution Mathematics for a 20mg Vial (1mL, 2mL, 3mL Diluent)

Accurate concentration calculations are vital when reconstituting a 20mg mass of lyophilized peptide to ensure precise volumetric micro-pipetting in vitro or exact milligram-per-kilogram dosing calculations in preclinical animal models. Reconstitution should always be conducted using bacteriostatic water (0.9% benzyl alcohol) or sterile 0.9% sodium chloride under a laminar flow hood. Researchers can utilize our online peptide reconstitution calculator to verify custom laboratory dilutions.

When adding 1.0 mL of diluent to a 20mg vial, the resulting stock solution yields a final concentration of 20.0 mg/mL (equivalent to 20.0 µg/µL). In standard micro-liter pipetting, a 10 µL aliquot delivers exactly 200 µg of active compound. If utilizing a standard 1 mL (100-unit) insulin syringe for volumetric measurement, each 1-unit graduation represents 0.20 mg (200 µg).

When adding 2.0 mL of diluent to a 20mg vial, the resulting concentration is 10.0 mg/mL (10.0 µg/µL). At this ratio, a 10 µL transfer pipettes 100 µg of MT-2, and each 1-unit mark on a 100-unit volumetric scale represents 0.10 mg (100 µg). This concentration is frequently selected for medium-scale laboratory assays as it offers a balanced trade-off between volume precision and stock liquid management.

When adding 3.0 mL of diluent to a 20mg vial, the concentration dilutes to 6.67 mg/mL (6.67 µg/µL). In this configuration, each 10 µL volume contains approximately 66.7 µg of compound, while a 1-unit mark on a standard 100-unit scale equates to 0.067 mg (66.7 µg). This lower concentration is optimal when micro-dosing low nanogram-to-microgram concentrations into cell culture media where volumetric precision is paramount.

Aliquoting Strategies & Handling Protocols

Reconstituting a single 20mg vial generates a substantial quantity of liquid stock solution. Repeatedly piercing the vial septum or subjecting the liquid stock to frequent temperature fluctuations accelerates peptide hydrolysis, aggregation, and loss of biological activity. To maintain maximum molecular integrity over extended laboratory projects, establishing a strict aliquoting protocol immediately post-reconstitution is strongly advised.

Following initial dissolution, the stock solution should be divided under sterile conditions into single-use micro-centrifuge tubes (e.g., polypropylene low-binding 0.5 mL tubes) matching the volumetric requirements of planned assay intervals. Aliquots should be snap-frozen in liquid nitrogen or a dry ice/ethanol bath and stored at -20°C or -80°C. Individual working tubes should be thawed only once prior to immediate application in experimental workflows, eliminating repeated freeze-thaw cycles.

Analytical Verification & Lot-Matched COA Standards

At PX1 Research, every batch of synthesized peptide undergoes rigorous analytical validation prior to release. Laboratory buyers can directly access every lot-matched Certificate of Analysis (COA) across our entire catalog. Analytical verification incorporates two fundamental chromatographic and spectroscopic techniques to guarantee identity and purity.

High-Performance Liquid Chromatography (HPLC) is conducted to verify chemical purity, ensuring that the primary compound peak represents >98.0% of total integrated peak area, with hydrophobic and hydrophilic impurities strictly quantified. Concurrently, Mass Spectrometry (MS) confirms exact molecular weight (1024.2 Da ± 1 Da), ruling out truncated sequences, deletion peptides, or incomplete cyclization. Furthermore, lot testing measures residual trifluoroacetate (TFA) salt levels and confirms endotoxin concentrations remain under <0.01 EU/mg, meeting institutional standards for sensitive cell culture and animal research.

Evaluating Vial Mass: 20mg vs 10mg Options

Selecting between a 20mg vial configuration and a 10mg vial depends primarily on experimental throughput, storage infrastructure, and operational timelines. A 20mg unit provides operational efficiency when multiple experimental plates must be prepared simultaneously from identical stock material. It minimizes standard deviation across batch runs by utilizing a single volumetric master mix.

Conversely, for lower-throughput laboratories or exploratory pilot studies, ordering smaller units such as the standard Melanotan II 10mg vial mitigates the risk of reconstituted liquid degradation over extended storage periods. Researchers can browse our complete research peptide catalog to review alternative unit sizes, comparative molecular specs, and availability across our standardized research offerings.

Comparative Analysis: Melanocortin Signaling Analog Class

Melanotan 2 belongs to a broader class of synthetic melanocortin receptor agonists researched for distinct physiological and cellular responses. Understanding the comparative structural modifications and receptor affinity profiles within this class assists researchers in selecting appropriate controls or experimental compounds.

For instance, Melanotan 1 (Afamelanotide) is a linear peptide analog of α-MSH that exhibits high selectivity for the MC1R subtype, making it a focused reference for pure skin pigmentation research without significant central melanocortin activation. In contrast, Bremelanotide PT-141 is a metabolite derivative of Melanotan II that lacks the C-terminal amide group; preclinical studies investigate PT-141 primarily for central MC3R and MC4R receptor binding pathways. Furthermore, smaller melanocortin-derived fragments like the tripeptide KPV peptide target downstream anti-inflammatory cascades independently of classical MC1R pigmentation pathways.

Thermal Stability, Lyophilization & Storage Protocol

Lyophilized Melanotan 2 demonstrates robust physical stability when stored under controlled environment conditions. The freeze-drying process removes free water, stabilizing the cyclic ring structure against spontaneous hydrolysis. Lyophilized vials should be kept in a desiccated freezer at -20°C for short-to-medium term storage (up to 12 months) or at -80°C for long-term storage (up to 24 months). Vials must be protected from direct light exposure.

Once reconstituted into liquid form, peptide stability declines significantly. Reconstituted aqueous solutions stored at refrigerated temperatures (2°C to 8°C) retain chemical stability for approximately 2 to 4 weeks, depending on diluent sterile parameters and buffer pH. Freezing reconstituted liquid solutions without cryoprotectants can cause mechanical stress on the peptide backbone; hence, aliquot planning remains the gold standard for preserving long-term activity.

Preclinical Research Applications & In Vitro Models

In vitro investigation of Melanotan 2 focuses predominantly on melanocyte cell cultures (such as B16-F10 melanoma cell lines or primary human melanocytes). In vitro data indicate that incubation with MT-2 induces dose-dependent increases in tyrosinase activity and melanin synthesis by elevating intracellular cAMP levels via MC1R activation. These assays allow quantitative measurement of melanogenic gene expression, including MITF (microphthalmia-associated transcription factor) upregulation.

In preclinical animal models, researchers evaluate systemic melanocortin receptor binding effects, skin tissue pigmentation dynamics, and central signaling responses. Animal studies suggest that peripheral administration leads to rapid localized and systemic melanin production in epidermal structures, serving as a robust model for evaluating photoprotective cellular mechanisms. All such studies are conducted strictly within controlled laboratory environments.

Institutional Procurement & Quality Assurance at PX1 Research

PX1 Research manufactures and distributes premium research-grade peptides exclusively for scientific inquiry, academic studies, and industrial R&D. Operating out of GMP-compliant facilities within the USA, our production processes adhere strictly to ISO 17025 accredited analytical standards. Every fill lot undergoes independent, third-party laboratory verification before entering inventory.

We support university departments, biotechnology organizations, and institutional laboratories with standardized batch tracking, comprehensive safety data sheets (SDS), and direct access to analytical documentation. Institutional buyers managing high-volume screening protocols can establish dedicated corporate accounts through our PX1 Research wholesale program or reference our centralized PX1 research repository for technical whitepapers and compound documentation.