MELANOTAN-1

Disclaimer: All articles and product details provided on this website are intended for educational and informational purposes only. The products listed here are for in-vitro research only. In-vitro studies are conducted outside of living organisms. These products are not intended as medicines or drugs and have not been approved by the FDA to prevent, treat, or cure any medical condition, ailment, or disease. The direct or indirect administration of these substances to humans or animals is unequivocally prohibited under applicable law.

What is MELANOTAN-1?

Melanotan-1 (also referenced in the literature as afamelanotide) is a synthetic linear tridecapeptide belonging to the melanocortin class of peptides. It is a structural analog of endogenous alpha-melanocyte-stimulating hormone (α-MSH), engineered with targeted amino-acid substitutions that distinguish it from the native hormone. Its defined primary structure is Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2, comprising 13 amino acid residues with an N-terminal acetyl cap and a C-terminal amide.

The molecule carries the empirical formula C78H111N21O19 and a molecular weight of 1646.87 g/mol, and is catalogued under CAS registry number 75921-69-6. Two key modifications differentiate the sequence from wild-type α-MSH: the replacement of the native methionine at position 4 with norleucine (Nle), and the substitution of the L-phenylalanine at position 7 with its D-enantiomer (D-Phe). These substitutions are widely documented as increasing the analog's resistance to enzymatic degradation and its conformational stability relative to the parent hormone.

Within the scientific literature, Melanotan-1 is studied as a melanocortin receptor ligand and is used as a reference compound in in-vitro investigations of the melanocortin signaling system and pigmentation biology. PX1 Research supplies this material strictly as a research chemical for in-vitro and laboratory investigation. It is not a drug, supplement, or article intended for human or veterinary use, and no physiological or therapeutic properties are represented here.

Reconstitution & handling

Melanotan-1 is shipped as a lyophilized (freeze-dried) powder and requires reconstitution in a compatible aqueous solvent before it can be handled in solution for laboratory work. Bacteriostatic water is the solvent most commonly cited for melanocortin peptides of this type; sterile water and dilute acetic acid solutions are also referenced in the literature for peptides bearing acidic and basic residues. To dissolve the solid, the chosen solvent is directed slowly down the inner wall of the vial rather than dispensed directly onto the peptide cake, then allowed to solubilize with gentle swirling. Vigorous agitation, vortexing, or shaking should be avoided, as mechanical shear and foaming can stress the peptide backbone.

As a 13-residue peptide containing polar and charged residues (Ser, Glu, Arg, Lys) alongside aromatic and hydrophobic residues (Tyr, Trp, Nle, Val), Melanotan-1 generally exhibits good solubility in aqueous buffers near neutral pH. Reconstituted material should be prepared fresh where feasible, kept cold during handling, and inspected visually to confirm a clear, particulate-free solution prior to use. All handling should follow standard laboratory practice for research chemicals of unknown biological activity.

Storage & stability

In its lyophilized form, Melanotan-1 is most stable and is best stored sealed and protected from light, moisture, and heat; long-term storage at -20°C is standard practice for research peptides, with brief periods at 2-8°C acceptable for short-term handling. Once reconstituted, the peptide is less stable in solution and should be held refrigerated at 2-8°C for near-term use or aliquoted and frozen for longer intervals to minimize degradation. Repeated freeze-thaw cycles should be avoided, as they can promote aggregation and loss of intact peptide; dividing solutions into single-use aliquots before freezing preserves integrity. Kept dry, cold, and dark, the lyophilized powder retains its characterized purity over extended storage.

How it's tested

Identity and purity of each Melanotan-1 lot are established by orthogonal analytical methods. Reversed-phase high-performance liquid chromatography (HPLC) quantifies chromatographic purity, with material released at ≥99% purity, and resolves process-related impurities and closely eluting peptide-related species. Mass spectrometry (MS) confirms molecular identity by measuring the observed mass against the theoretical mass derived from the C78H111N21O19 formula (1646.87 g/mol), verifying that the correct sequence and terminal modifications are present. A Certificate of Analysis (COA) documenting these results is available for the material, providing lot-specific traceability of purity and identity for laboratory records.

Frequently asked questions

What is Melanotan-1?

Melanotan-1 (afamelanotide) is a synthetic 13-amino-acid linear analog of alpha-melanocyte-stimulating hormone (α-MSH). It is supplied as a lyophilized research-grade peptide under CAS 75921-69-6 for laboratory research use only.

How does its sequence differ from native α-MSH?

Its documented sequence, Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2, carries a norleucine substitution at position 4 and a D-phenylalanine at position 7, along with an N-terminal acetyl group and C-terminal amide. These modifications are cited as improving stability relative to the parent hormone.

What is the molecular formula and weight?

Melanotan-1 has the empirical formula C78H111N21O19 and a molecular weight of 1646.87 g/mol, with CAS registry number 75921-69-6.

How is Melanotan-1 reconstituted for research?

The lyophilized powder is dissolved in a compatible aqueous solvent such as bacteriostatic or sterile water, added slowly down the vial wall and swirled gently rather than shaken. As a peptide with both polar and hydrophobic residues, it generally dissolves well in aqueous buffers near neutral pH.

How should it be stored?

Store the lyophilized powder sealed at -20°C, protected from light and moisture. After reconstitution, keep it refrigerated for near-term use or frozen in aliquots, and avoid repeated freeze-thaw cycles.

How is purity and identity verified?

Each lot is analyzed by reversed-phase HPLC for purity (≥99%) and by mass spectrometry to confirm molecular identity against the theoretical mass. A lot-specific Certificate of Analysis (COA) is available.