Melanotan I: Reference Overview and Reconstitution Notes

July 9, 2026

Melanotan I

What it is

Melanotan I, known by its International Nonproprietary Name afamelanotide, is a synthetic 13 amino acid peptide and a structural analogue of the naturally occurring hormone alpha-melanocyte stimulating hormone (alpha-MSH). It acts with high selectivity as an agonist at the melanocortin-1 receptor (MC1R), the receptor associated with eumelanin production in the skin.

Research context and categorization

Melanotan I is grouped under the skin, pigment, and photoprotection category of research compounds, alongside broader melanocortin receptor work. Because it selectively activates MC1R, it is studied in the context of stimulating eumelanin synthesis in the epidermis, which is investigated as a way to increase the skin's natural light-absorbing pigment.

In its FDA-approved prescription form (afamelanotide, marketed as Scenesse by Clinuvel Pharmaceuticals), it is used to reduce phototoxic pain reactions in patients with erythropoietic protoporphyria (EPP), a rare inherited light-sensitivity disorder. Beyond that approved indication, the compound has been investigated for and is commonly discussed in relation to conditions such as vitiligo (often studied together with narrowband UV-B phototherapy), polymorphous light eruption, and solar urticaria. These additional uses remain investigational and are not confirmed or approved benefits. As a raw lyophilized research powder, Melanotan I is not the same as the approved pharmaceutical product and is not approved for human use or compounding.

Status

Regulatory status: FDA-approved for a specific indication (afamelanotide / Scenesse, approved October 2019 for phototoxic reactions in erythropoietic protoporphyria). Raw research-grade Melanotan I powder is research-only and not FDA-approved for human use. There is no FDA-approved cosmetic tanning indication.
Sport status: Reported as prohibited under the WADA Prohibited List, classified within Section S2 (peptide hormones, growth factors, related substances and mimetics) as an alpha-MSH analogue and melanocortin agonist. It is detectable in urine and blood by LC-MS/MS methods.

Reconstitution notes (general)

Lyophilized peptides are prepared by adding bacteriostatic water to the powder in the vial. The resulting concentration is simply the milligrams in the vial divided by the millilitres of bacteriostatic water added. For example, 10 mg reconstituted with 2 mL gives 5 mg/mL. A reconstitution calculator is available at /pages/tools to work out the concentration for any vial size and water volume.

Dilution and handling notes (compound-specific)

The FDA-approved product, Scenesse, is a solid subcutaneous implant and is not reconstituted. The notes below apply only to lyophilized Melanotan I powder as sold for research reference, not to the approved implant.

Reference material commonly cites a 10 mg vial reconstituted with 1 to 3 mL of bacteriostatic water, most often 2 mL. A 1:1 volume (for example 10 mL into a 10 mg vial, giving 1 mg/mL) is also documented. Adding more water yields a more dilute, easier-to-measure solution, while less water gives a smaller total volume at higher concentration. The 2 mL / 5 mg/mL point is frequently described as a practical middle ground: measurable with standard graduated syringes while avoiding both very dilute and very concentrated extremes.

Melanotan I generally dissolves readily. Reports describe the powder cake going into solution within a minute or two, yielding a clear, colorless to faintly amber liquid with no visible particles. Unlike some concentrated peptides that tend to gel or turn cloudy, Melanotan I at these ratios usually does not precipitate, so a cloudy or particulate result is treated as a sign of a handling problem rather than normal behavior. The practical technique to keep it clean is to run the water slowly down the inside glass wall rather than jetting it directly onto the powder, then swirl gently. Do not shake. Shaking applies shear force that can degrade the peptide and produces foam that makes accurate volume reads difficult. If faint haze or small white flecks appear at higher concentration, chilling the vial at 2 to 8 C for a short period and then swirling again commonly helps it finish dissolving.

Handling quirks worth noting: the peptide is light-sensitive, so both the powder and the mixed solution are kept out of direct light, and it is sensitive to heat and to the mechanical stress of a forceful water stream, which is why gentle addition and gentle mixing are the standard.

Handling and storage

Store reconstituted solution refrigerated at 2 to 8 C and keep it out of direct light. Wipe the rubber stopper with an alcohol prep pad before drawing from the vial and let it air-dry, and label the vial with the mix date so its age is easy to track. Reconstituted material is generally considered usable for roughly a four-week (about 28 day) refrigerated window. Discard the vial if the contents become cloudy or discolored, or if floaters or particulates appear.

Tools and supplies

For laboratory and research reference only. Educational content, not medical, dosing, injection, or therapeutic guidance, and not intended for human or animal use. Any research uses described are investigational and not confirmed or approved benefits. Confirm anything involving health with a licensed professional. References linked above.