Melanotan I

Melanotan I (Afamelanotide) is a thirteen-amino-acid linear analogue of α-MSH, with modifications that make it more stable than the natural hormone. It is a melanocortin receptor agonist that binds predominantly to the MC1 receptor.

Mechanism of action under investigation

Research is being carried out into melanogenesis – the process by which the cell produces the pigment melanin – via binding to the MC1 receptor on melanocytes. Because Melanotan I binds more selectively to this receptor than the more potent Melanotan II, it is a more targeted model molecule for pigmentation research.

This description relates to the mechanism of action as studied in research and does not constitute evidence of efficacy or safety in humans.

Its greater stability compared with natural α-MSH makes Melanotan I more practical to study: the molecule remains intact for longer in an experimental setup. This property, combined with its relatively selective receptor binding, explains why it is a widely used model molecule in pigmentation research. For researchers, this offers a more targeted point of intervention than broader melanocortin agonists.

Afamelanotide is the clinically investigated form of Melanotan I. Under the brand name Scenesse, afamelanotide has been approved by the FDA (2019) and the EMA (2014) for a specific, rare condition — erythropoietic protoporphyria (EPP) — to reduce light sensitivity.

• Research focus: melanogenesis via the MC1 receptor.
• Research focus: pigmentation and sun protection (clinical, in the context of EPP).
• Research focus: selectivity with regard to Melanotan II.

Status and context

Important: the approval of afamelanotide relates solely to its medical use in EPP; there is no approved indication for cosmetic tanning. The Melanotan I offered here is a research compound, intended solely for laboratory and research purposes — it is not a medicinal product and is not a tanning agent. Always document purity and batch number during research.

The clinical development of afamelanotide illustrates how an α-MSH analogue has been investigated in a strictly medical, controlled setting and ultimately approved for one specific condition. That process is separate from the investigational compound offered here, which is intended solely for laboratory use. The distinction between the approved medicinal product afamelanotide and this investigational compound is therefore essential for accurate and correct communication.

Melanotan I is supplied as a lyophilised powder and reconstituted in the laboratory using bacteriostatic water. The steps below describe only the laboratory procedures for research purposes.

1. 1Allow the vial and the bacteriostatic water to reach room temperature.
2. 2Wipe the rubber stoppers of both vials with an alcohol wipe.
3. 3Allow the bacteriostatic water to run slowly down the side of the vial; do not direct it straight onto the powder.
4. 4Gently swirl the vial until everything has dissolved; do not shake.
5. 5Store the solution in the fridge and label it with the date and batch number.

You can find supplies such as bacteriostatic water, insulin syringes and alcohol wipes under ‘Lab & Accessories’. This is laboratory guidance and is expressly not intended as advice on use or dosage.

A rigorous research context

As melanocortin agonists act on a broad signalling system, this material should be handled in a controlled research environment. Standardise your procedures and document the method, concentration and batch number for each experiment.

Prepare only the quantity you need for your research and store the solution in a cool place immediately; document the method, concentration and batch number for each experiment. Follow standardised procedures to ensure that observations remain traceable between experiments.

Store Melanotan I in lyophilised (powder) form in a cool, dark place for maximum stability.

Practical storage tips

• Powder form: freezer (-20 °C) for long-term storage; fridge (2–8 °C) for short-term storage.
• After reconstitution: store refrigerated (2–8 °C) and use within a few weeks.
• Avoid direct light, heat and repeated temperature changes.
• Write the reconstitution date and batch number on the vial.

Careful storage preserves the purity and integrity of the research material.

Stable, cool and dark storage ensures reliable, reproducible measurement results. Check the solution for clarity before use.