Melanotan II
Melanocortin peptide that promotes tanning, fat loss, and enhanced libido
Clinical Research Score: 4/5 — Studied in early human trials, and its close analog afamelanotide is FDA-approved, though MT-II itself is not.
Categories: Skin & Hair, Sexual Health, Weight Loss / Metabolic
What is Melanotan II?
Melanotan II is the multi-tasker of the peptide world. It was originally studied for skin cancer prevention — the idea being that if you could develop a protective tan without UV exposure, you'd reduce skin cancer risk. But people quickly discovered it does much more.
The tanning effect is undeniable. People develop a deep, natural-looking tan with far less sun exposure than usual. Skin takes on a warm, bronzed tone that looks natural rather than artificial. But the side benefits caught everyone's attention: appetite decreases noticeably, making it useful for body composition goals. Libido increases significantly, with many people reporting enhanced arousal and desire.
Here's how to actually run it. Inject right before bed, because the most common side effect is a wave of nausea — dose as you're winding down for sleep and you'll usually sleep straight through it. The next day, get out in the sun or use a tanning bed, and repeat that for three to five days; the color builds fast, and most people go noticeably darker within that window. Start low and titrate up, since the tanning effect is cumulative and long-lasting. One honest trade-off to know up front: it darkens everything, so any moles, freckles, and age spots you already have will get darker too — plenty of people decide the tan is well worth it, but it's better to go in expecting it.
How Melanotan II works
Melanotan II activates multiple melanocortin receptors throughout your body. MC1R activation in the skin stimulates melanocytes to produce melanin — the natural pigment that creates a tan and protects against UV damage. MC4R activation in the brain reduces appetite and enhances sexual arousal. MC3R activation promotes fat oxidation. The result is a single compound that simultaneously darkens skin, reduces hunger, increases desire, and promotes fat metabolism.
Scientific overview
Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that activates melanocortin receptors MC1R through MC5R. It stimulates melanogenesis (skin darkening), reduces appetite, enhances libido, and promotes fat oxidation. Originally developed for skin cancer prevention, it has gained popularity for its cosmetic tanning and body composition effects.
Dosing
- Starting dose: 100 mcg per day
- Common dosage range: 250-500 mcg per day (loading), then as needed
- Administration: Subcutaneous
- Half-life: ~36 hours
- Frequency: Daily during loading, then 1-2x per week maintenance