What is melanotan II?

What is melanotan II?

Melanotan II is a synthetic agonist of the melanocortin receptors supplied for research purposes in a pre-filled multi-dose pen. It acts on the melanocortin pathway that regulates pigmentation.

It is studied in pigmentation research through activation of the melanocortin receptors. Research results vary; the peptide is not a cosmetic product and is supplied for laboratory research only.

Mechanism of action

Melanotan II is a cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH), designed at the University of Arizona in the 1980s to be more potent and more stable than the natural hormone. It is a non-selective agonist of the melanocortin receptors: it activates MC1R, MC3R, MC4R and MC5R.

Action on MC1R in melanocytes increases the synthesis of eumelanin, the dark pigment, and is the basis of its research in pigmentation and photoprotection. Action on MC4R, in the hypothalamus, explains the effects on appetite and on sexual function that appeared in the first clinical trials and that gave rise to the development of bremelanotide.

Its lack of selectivity is the reason it has never been authorised: the selective MC1R analogue that was authorised in Europe for erythropoietic protoporphyria is afamelanotide, a different compound.

What the published research says

1. 1.
   Dorr et al., Life Sci, 1996PMID 8637402

   First phase 1 pilot trial in volunteers: daily subcutaneous doses produced measurable skin darkening with very little sun exposure; the adverse effects were nausea, stretching and yawning, and spontaneous erections.

2. 2.
   Wessells et al., J Urol, 1998PMID 9679884

   Placebo-controlled crossover study in 10 men with psychogenic erectile dysfunction: melanotan II induced erections in most, with nausea and yawning as accompanying effects.

3. 3.
   Hadley, Peptides, 2006PMID 16412534

   Historical review of the development of the melanocortin peptides, from Melanotan I and II to the selective analogues, with the clinical trials and the attempts at commercialisation.

What side effects does melanotan II have?

• Nausea and facial flushing, more common with the first doses and usually settling when starting from a low initial dose.
• Darkening of existing moles and freckles, and changes in appetite, reported in the literature.
• Mild, transient injection-site reactions.

How is melanotan II dosed?

A daily loading phase of 200 mcg a day, climbing to a maximum of 500 mcg a day, followed by maintenance at 200 mcg twice a week. Start at 200 mcg to gauge sensitivity before stepping up. The pen sets each dose.

Storing the pen

Keep the pen between 2 and 8 °C, protected from light and never frozen. Unopened it has a 24-month shelf life; from the first puncture, 12 months. If no fridge is available it keeps for up to 30 days at room temperature, below 30 °C. Let it reach room temperature before giving a dose. The dial sets each dose directly in milligrams: there is no reconstitution, no bacteriostatic water and no volume calculation.

How do you get melanotan II?

Body Pharm's melanotan II pen is a sealed, HPLC-verified device with a published certificate of analysis (CoA). Shipping is to Spain only: a single option at €15, delivered in 3–5 working days. It is sold exclusively for research purposes.

How much does melanotan II cost per month?

From 89 € per pen: a single pen covers a multi-week research cycle of loading and maintenance.

How it compares

Within the skin category, melanotan II acts on pigmentation and GHK-Cu on the dermal matrix; they share no mechanism. As of the last review of this page (October 2026) it is not authorised as a medicine in any jurisdiction and it is sold exclusively for research.

The scheme of daily loading followed by weekly maintenance comes from research practice and the early trials, not from a phase 3 programme; the most cited adverse effects, nausea and flushing, are concentrated in the first doses.

• How to dose melanotan II
• What is GHK-Cu?
• Peptides for skin