Molecular Characteristics
Complete Specifications
Structural Composition
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-NH₂
Physical Properties
Melanotan II is a synthetic cyclic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). Cyclization between aspartic acid and lysine residues enhances conformational stability and resistance to enzymatic degradation compared to linear analogs. Additional modifications including norleucine substitution and D-phenylalanine incorporation contribute to structural persistence under controlled research conditions. Lyophilized storage and protection from moisture, light exposure, and repeated freeze–thaw cycles help preserve peptide integrity and maintain analytical consistency during laboratory applications.
Analysis & Documentation
Identity
Each production lot is checked against the reference structure recorded for this compound:
- Classification — Synthetic cyclic heptapeptide
- Molecular formula — C₅₀H₆₉N₁₅O₉
- Expected mass — ~1,024.2 Da
- CAS registry — 121062-08-6
- Chain length — 7 amino acids (cyclic, modified)
- PubChem CID — 92432
Analytical Methods
Testing is carried out per lot by an independent laboratory. The methods measure what the material is and how much of it is the target compound:
- RP-HPLC — reverse-phase separation of the target from process-related impurities; purity is reported as area percent of the main peak
- Mass spectrometry — observed mass compared against the expected molecular mass above
- Retention time — compared against a reference standard run under the same conditions
- Chromatogram — reproduced on the certificate so the peak and any shoulders can be inspected directly
Material & Documentation
What arrives, and how to tie it back to its paperwork:
- Appearance as supplied — White to off-white lyophilized powder
- Solubility — Water, buffered aqueous solutions (e.g., PBS)
- Lot number — printed on the container label and used to look up the certificate
- Certificate — indexed by lot at Certificates of Analysis
Laboratory Handling and Storage Protocols
Lyophilized Powder Storage
- Store at –20°C to –80°C in the original, sealed vial
- Protect from light exposure and moisture
- A desiccated storage environment is recommended
- Stability data suggests extended stability when stored at −20 °C or below.
Stability Characteristics
Melanotan II is a synthetic peptide research compound that demonstrates stable handling characteristics when managed according to standard peptide laboratory protocols. Proper cold storage of the lyophilized material, protection from light, careful reconstitution, and minimized freeze–thaw exposure help preserve structural integrity and solubility. When handled appropriately, Melanotan II supports consistent use in in vitro and analytical research applications.
Frequently Asked Questions
What is Melanotan II?
Melanotan II is a synthetic cyclic heptapeptide, Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-NH₂ (molecular formula C₅₀H₆₉N₁₅O₉, molecular weight ~1,024.2 Da; CAS 121062-08-6, PubChem CID 92432). It is supplied as a white to off-white lyophilized powder.
How does Melanotan II differ from Melanotan I?
Melanotan II is a cyclic peptide of 7 residues, closed between its aspartic acid and lysine side chains; Melanotan I is a linear 13-residue peptide. They carry different molecular formulas, masses and CAS registry numbers.
Is Melanotan II naturally occurring?
No. Melanotan II is a fully synthetic cyclic peptide that contains residues not used in natural protein synthesis (norleucine and D-phenylalanine), and it does not occur in nature.
How is Melanotan II supplied?
Melanotan II is typically supplied as a lyophilized (freeze-dried) powder in sealed research vials to preserve stability during storage and shipment.
How should lyophilized Melanotan II be stored?
Lyophilized Melanotan II should be stored:
-
Long-term: −20 °C to −80 °C
-
Short-term: 2–8 °C
Keep vials sealed and protected from light and moisture until use.
Does Melanotan II require a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis (COA) should be available for each batch of Melanotan II, verifying identity and purity to ensure research quality and traceability.
Is Melanotan II FDA-approved?
No. Melanotan II is not FDA-approved as a drug, supplement, or therapeutic product. It is sold exclusively as a research compound and must not be marketed or used for diagnostic, therapeutic, or consumption purposes.
This product is not for human consumption. It is sold strictly for research and educational purposes and is not intended to diagnose, treat, cure, or prevent any disease.
Any clinical data or research information referenced on this page is derived from peer-reviewed scientific literature and official publications. This information is provided for educational reference only and does not constitute medical advice or product claims.
By purchasing this product, you acknowledge that you are a qualified researcher and agree to use it in full compliance with all applicable laws and regulations.
