Melanotan II

Cyclic Melanocortin Analog

Half-life: ~1–2 hours

MT-2MT-II

Research Profile

Research Depth

Potency

Half-Life Score

Selectivity

Stability

Relative research assessments — educational reference only.

Target Receptors

MC1RMC3RMC4RMC5R

Critical Research Warning

For educational reference only. Non-selective MC receptor activation produces a broad side-effect profile. Long-term melanocyte stimulation has unknown effects on melanoma risk. Not FDA-approved.

PeptidePlaza Entry #020

"A potent cyclic analog of α-MSH that activates melanocortin receptors broadly. Studied for UV-independent melanogenesis, appetite suppression, and as the parent compound of PT-141 (Bremelanotide)."

Full Description

Melanotan II is a cyclic synthetic analog of alpha-melanocyte stimulating hormone (α-MSH) with a D-Phe substitution at position 7 and a lactam bridge. It is a non-selective melanocortin receptor agonist (MC1R–MC5R). Research encompasses: melanogenesis via MC1R without UV exposure, appetite suppression and metabolic effects via MC3R/MC4R, arousal via hypothalamic MC4R (basis of its metabolite PT-141/Bremelanotide), and reduced alcohol and compulsive behaviour in animal models. Due to its non-selectivity and potency, it has a broader side-effect profile than selective analogs.

Mechanism of Action

Non-selective agonism at MC1R (melanogenesis), MC3R (energy homeostasis), MC4R (appetite/arousal/CNS), MC5R (exocrine glands). Stimulates melanocyte dendrite elongation and eumelanin synthesis independent of UV radiation.

Reported Benefits

• UV-independent melanogenesis via MC1R activation
• Appetite suppression and ethanol intake reduction
• Parent compound for PT-141 development

Potential Side Effects

• Nausea and facial flushing
• Spontaneous arousal (CNS-mediated)
• Darkening of pre-existing nevi and freckles

Frequently Asked Questions

How does Melanotan II induce tanning?▼

By activating MC1R receptors on melanocytes, Melanotan II stimulates eumelanin (dark pigment) production independent of UV exposure. This results in darkening of skin without the DNA damage caused by UV radiation — though the pigment is not a substitute for sun protection.

What are the main side-effect concerns?▼

Melanotan II is non-selective, stimulating all five melanocortin receptors. This creates a broad profile: nausea and flushing (common), spontaneous arousal (MC4R), darkening of moles/freckles (MC1R), and appetite suppression. Its non-selectivity limits therapeutic utility compared to selective analogs like PT-141 or setmelanotide.

For Research Reference Only

Not medical advice. Peptides may be regulated or restricted in your jurisdiction.