Melanotan II (MT-II) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It acts as a non-selective agonist at melanocortin receptors — specifically MC1R, MC3R, MC4R, and MC5R. Researchers studying melanocortin pathways, energy homeostasis, integumentary physiology, and hypothalamic signaling frequently use MT-II in controlled laboratory settings. For a comprehensive background on peptide mechanisms, see our Complete Guide to Peptides.
Researchers who want to buy melanotan ii nasal spray benefit from the nasal spray formulation, which offers a convenient, pre-measured delivery format. Each spray delivers a precise 100mcg dose, eliminating the reconstitution step required for lyophilized vial peptides. The peptide remains stable in solution at appropriate storage temperatures, making it well-suited for multi-week research protocols where dose consistency is critical.
Those looking to buy melanotan ii nasal spray for research benefit from an already-prepared solution that minimizes handling steps, reduces contamination risk, and simplifies dosing records. PSPeptides’ formulation is manufactured under strict quality controls in a US-based facility, with each batch independently tested before release.
Detailed Mechanism of Action
Melanotan II exerts its effects by binding to melanocortin receptors — G protein-coupled receptors (GPCRs) coupled to Gs proteins. Upon receptor engagement, MT-II activates adenylate cyclase, raising intracellular cyclic AMP (cAMP) levels and triggering downstream protein kinase cascades. In melanocytes, elevated cAMP activates protein kinase A (PKA), which phosphorylates the transcription factor CREB and upregulates MITF — the master regulator of melanocyte differentiation — leading to increased tyrosinase expression and enhanced melanogenesis. This molecular pathway is why researchers frequently buy melanotan ii nasal spray to study pigmentation biology at the cellular level.
At the MC4R subtype expressed in hypothalamic neurons, MT-II modulates the leptin-melanocortin axis, influencing feeding behavior and energy expenditure. Research has demonstrated that MC4R agonism reduces food intake and increases basal metabolic rate in rodent models, effects attributed to downstream activation of PI3K/Akt/mTOR pathways in arcuate nucleus neurons. These mechanisms are distinct from those at MC1R, reflecting the receptor subtype-specific pharmacology of downstream signaling networks — making pan-melanocortin agonists like MT-II especially valuable for comparative receptor studies.
MT-II binding at MC3R, expressed in the hypothalamus and peripheral tissues, has been linked to natriuretic and cardiovascular regulatory functions in preclinical research. The interaction with MC5R — found in exocrine glands, skin, and immune cells — points to roles in sebaceous gland physiology and immune cell modulation. Because MT-II is a non-selective agonist across these receptor subtypes, researchers can use it to study cumulative pan-melanocortin activation or pair it with selective antagonists to isolate individual receptor contributions.
The peptide’s cyclic structure, stabilized by a lactam bridge between lysine and aspartate residues, confers greater conformational rigidity and receptor binding affinity compared to linear α-MSH analogs. This structural feature significantly extends the in vitro stability and receptor occupancy duration, making MT-II a preferred tool peptide for mechanistic melanocortin research. The nasal spray format preserves the peptide’s structural integrity while delivering a consistent dose with each actuation.
Published Research Supporting MT-II Studies
The scientific literature on Melanotan II spans more than three decades and covers a broad range of biological systems. Seminal work by Hadley and colleagues in the early 1990s established the structure-activity relationships of melanocortin peptide analogs, demonstrating that the cyclic MT-II structure produced more potent and prolonged receptor activation than linear α-MSH. These foundational studies created the template for modern melanocortin tool peptide development and set the purity and formulation standards that laboratories expect when they buy melanotan ii nasal spray for controlled research today.
A 2000 study by Wessells et al. published in Neuroscience examined MC4R-driven pro-erectile pathways in rats, showing that intracerebroventricular MT-II infusion produced dose-dependent physiological responses blocked by selective MC4R antagonists. Subsequent pharmacology work published in peer-reviewed urology journals found MT-II to exert centrally mediated effects via melanocortin pathways, validating the melanocortin system as a target in sexual function research. These studies are accessible via PubMed (Wessells 2000) and represent foundational references for MT-II CNS researchers.
More recent work published in PLOS ONE (2019) investigated MT-II’s role in inflammatory pain modulation via MC3R and MC4R pathways, noting anti-nociceptive effects in murine models. A further study in the Journal of Neuroinflammation (2021) explored MC4R-mediated neuroprotective effects, expanding the research use of buy melanotan ii nasal spray applications into neuroimmunology and pain research. For the most current literature, researchers can search PubMed for MT-II and melanocortin research.
Melanotan II Nasal Spray vs Alternatives
| Feature |
MT-II Nasal Spray (PSPeptides) |
MT-II Lyophilized Vial |
Afamelanotide (MT-I) |
| Format |
Ready-to-use spray solution |
Requires reconstitution |
Typically injectable implant |
| Dose Precision |
100mcg per actuation |
Variable (user-measured) |
Fixed implant dose |
| Receptor Selectivity |
MC1R, MC3R, MC4R, MC5R |
Same |
Primarily MC1R selective |
| Analytical Purity |
99%+ (HPLC & MS verified) |
Varies by supplier |
Pharmaceutical grade |
| Preparation Time |
Zero — ready immediately |
15–20 min reconstitution |
Requires clinical procedure |
| Stability |
Refrigerated; stable in solution |
Long shelf-life lyophilized |
Pharmaceutical storage |
| COA Included |
Yes — batch-specific |
Varies by vendor |
Pharmaceutical standards |
| Best For |
Multi-receptor MC studies; convenience |
Custom-dose experiments |
MC1R-specific pigmentation studies |
Handling the Nasal Spray Format in the Laboratory
When researchers buy melanotan ii nasal spray from PSPeptides, they receive a ready-to-use formulation — no reconstitution is required. The bottle contains 10mg of MT-II in sterile solution, pre-loaded into the spray actuator mechanism delivering 100mcg per spray (100 sprays total per bottle). Before beginning any experiment, prime the pump by actuating 2–3 times into a waste container until a consistent fine mist is produced. Record the number of priming actuations to maintain accurate total dose tracking.
For laboratory handling, maintain the bottle in a vertical, upright position. Clean the nozzle tip with a clean, dry tissue after each use and replace the protective cap immediately. During extended experiments, document each actuation and the remaining spray count to maintain accurate records of dose exposure. The spray format eliminates pipette measurement error and reduces variability compared to manually reconstituted solutions, an advantage for studies requiring tight dose reproducibility across experimental animals or subjects. For general peptide handling best practices, see our Peptide Reconstitution Guide and Peptide Storage Guide.
Storage and Stability Guidelines
The buy melanotan ii nasal spray formulation should be stored at 2–8°C (standard laboratory refrigerator temperature) in the original container. Avoid freezing — repeated freeze-thaw cycles can alter solution homogeneity and peptide stability. Protect the bottle from direct light exposure, as prolonged UV exposure can degrade the peptide’s tryptophan and histidine-containing residues. When kept under proper conditions, the formulation remains stable for the duration of the research protocol as documented on the batch-specific COA. For a comprehensive reference on peptide storage principles, see our Peptide Storage and Stability Guide.
During transport between laboratory spaces or buildings, keep the spray bottle cool in an insulated container with an ice pack. Do not leave at room temperature for periods exceeding 30 minutes without active cooling. For multi-day or multi-week experiments, remove the spray bottle from cold storage only as needed for each experimental session. If the solution appears cloudy, discolored, or contains visible particulates that do not disperse on gentle agitation, the batch should not be used and PSPeptides support should be contacted immediately. Researchers can refer to our article on How to Tell If a Peptide Has Degraded for additional guidance.
Certificate of Analysis — What to Expect
Every shipment when researchers buy melanotan ii nasal spray from PSPeptides includes a batch-specific Certificate of Analysis (COA). The COA documents: peptide identity confirmed by mass spectrometry, purity determined by reverse-phase HPLC chromatography, lot number, manufacturing date, and physical appearance assessment. Analyses are performed by an independent, accredited third-party analytical laboratory — not self-reported — ensuring the objectivity and reproducibility that institutional research programs require.
Researchers should review the COA before initiating experiments to confirm that the batch meets their protocol’s purity requirements. If you need guidance interpreting HPLC chromatograms, retention times, or mass spectral data, our detailed reference is available at: How to Read a Peptide Certificate of Analysis. PSPeptides retains COA data for all historical batches, supporting longitudinal research projects that require traceability and lot-to-lot comparison. Contact support for COA records on any previous order.
Why Researchers Choose PSPeptides for MT-II
- US Manufactured: All peptides are synthesized and quality-controlled in the United States, ensuring regulatory compliance and supply chain transparency.
- Third-Party Tested: Independent HPLC and mass spectrometry verification — not self-reported purity claims. Every batch is tested before release.
- Fast Shipping: Free UPS 2nd Day Air on orders over $200; same-day dispatch for orders placed before 2 PM EST.
- Flexible Payments: Credit cards, Afterpay, Klarna, Apple Pay, and Google Pay all accepted for research purchases.
- 7-Day Research Support: Team available via email, phone, or text throughout the week to assist with product selection, COA interpretation, and research questions.
When you buy melanotan ii nasal spray from PSPeptides you are sourcing a product with verified analytical processes. Researchers who buy melanotan ii nasal spray here benefit from transparent supply chain documentation and a commitment to research-grade standards. PSPeptides is sourcing from a vendor with verified analytical processes, transparent supply chain documentation, and a commitment to research-grade standards. Many institutional researchers and independent scientists choose PSPeptides after comparing alternatives — our Best Peptide Companies 2026 guide and How to Choose a Research Peptide Supplier article provide objective criteria for vendor evaluation. For regulatory context, see our guide on Research Peptides Legal Status in 2026.
Frequently Asked Questions
What is Melanotan II Nasal Spray used for in research?
Melanotan II Nasal Spray is used by researchers studying melanocortin receptor pharmacology, pigmentation biology, energy homeostasis, and hypothalamic signaling. MT-II acts as a non-selective melanocortin receptor agonist at MC1R, MC3R, MC4R, and MC5R, making it a versatile tool for multi-receptor pathway studies. All research use must comply with applicable institutional and regulatory guidelines for peptide research compounds.
How does the nasal spray format differ from MT-II vials?
Unlike lyophilized vials that require reconstitution with bacteriostatic water and precise volume measurement, the MT-II nasal spray arrives ready-to-use with a pre-measured 100mcg per actuation dose. This eliminates preparation variability and reduces contamination risk during the reconstitution process. When researchers buy melanotan ii nasal spray rather than a vial, they gain dosing consistency and time efficiency that supports multi-day experimental protocols. See our guide to bacteriostatic water for context on the vial reconstitution process.
What purity level does PSPeptides’ Melanotan II Nasal Spray achieve?
PSPeptides Melanotan II Nasal Spray achieves 99%+ purity as verified by independent third-party HPLC analysis and mass spectrometry. A batch-specific Certificate of Analysis is included with every order, documenting purity, molecular weight confirmation, and physical appearance. This level of analytical verification is essential for research reproducibility, institutional compliance, and scientific data integrity across longitudinal experiments.
How should Melanotan II Nasal Spray be stored in a laboratory setting?
Store the nasal spray bottle at 2–8°C (standard refrigerator temperature), protected from direct light and freezing. Maintain the bottle in an upright position and replace the protective cap after each use. Under correct conditions, the formulation remains stable for the duration documented on the batch-specific COA. For comprehensive storage guidance applicable to all research peptides, refer to our Peptide Storage Guide.
How many doses does one bottle provide?
Each bottle of Melanotan II Nasal Spray from PSPeptides contains 10mg of MT-II formulated at 100mcg per actuation, providing 100 doses per bottle. Allow for 2–3 priming actuations before first use to ensure consistent spray delivery. The total usable dose count per bottle is therefore approximately 97–98 experimental doses after priming. For questions about dosing protocols in specific research designs, contact the PSPeptides support team directly.
Related Research Resources
All PSPeptides products are sold exclusively for laboratory and research use. Not intended for human consumption.
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