Melanotan II

▸ Overview

Melanotan II is a synthetic cyclic analog of α-MSH (melanocyte-stimulating hormone). It is investigated for its ability to stimulate melanogenesis (tanning), its effect on libido and on satiety. It acts on the melanocortin receptors MC1R, MC3R, MC4R and MC5R.

▸ Mechanism of action

• A cyclic analog of α-MSH (alpha-melanocyte-stimulating hormone), with greater potency and half-life than the endogenous molecule.
• Acts on MC1R in melanocytes: stimulates the synthesis of eumelanin (dark pigment), producing tanning without sun exposure.
• Acts on MC4R in the hypothalamus: regulates appetite (anorexigenic effect) and modulates sexual function.
• Acts on MC3R and MC4R in the central nervous system: produces erections (men) and increased sexual desire (both sexes).
• The induced tanning begins 5–10 days after starting, with minimal sun or UV exposure required to activate the melanocytes.
• Has a potential protective effect against UV damage by increasing eumelanin production before sun exposure.

▸ Administration

• Subcutaneous route: injection in the abdomen or thigh with fine needles.
• Reconstitution: lyophilized powder with bacteriostatic water.
• Storage: refrigerate at 2–8 °C; protect from direct sunlight.

▸ Timing

• Usually administered at night to minimize the nausea effect.
• The first dose should always be the smallest to assess tolerance.
• No specific fasting restrictions.

▸ Dosing & cycles

• Loading phase: progressive doses until the desired level of melanization is reached.
• Maintenance phase: reduced doses at a lower frequency.
• Tanning effects may be seen 5–10 days after starting.

▸ Combinations

• Melanotan II + PT-141: a melanocortin combination with dual action on pigmentation and libido.
• Sometimes combined with recovery peptides in compound protocols.

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