What are the uses of Melanotan II?

Skin tanning with reduced UV exposure. Libido and erectile function. Appetite suppression (secondary)

Sexual HealthResearch Chemical

Melanotan II

Also known as: MT-2, MT-II

Melanocortin agonist that darkens skin and boosts libido — one of the most widely used research peptides in the biohacking world.

Subcutaneous injection

Sexual Health

Melanotan II

Subcutaneous injectionResearch Chemical

Research use only, not FDA-approved. Linked to nausea, blood-pressure changes, and changes in moles/melanoma risk; dermatologic monitoring is advised in the literature.

Overview

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH). It stimulates melanin production for tanning and also acts on melanocortin receptors in the brain, producing pro-erectile and libido-enhancing effects. It is heavily discussed and sold in the research-peptide market despite lacking approval.

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH), the hormone that tells your skin to produce pigment. Because it is a non-selective melanocortin agonist, it activates several receptors at once: MC1R (which drives melanin production and tanning) and MC4R (which sits in the brain and influences sexual arousal and appetite). That dual action is why the same compound is used both for cosmetic tanning and for libido — and why its side-effect profile is broader than more targeted peptides.

The original melanocortin research at the University of Arizona was aimed at safer sun protection and at treating sexual dysfunction. That program ultimately produced the FDA-approved drug bremelanotide (PT-141), while Melanotan II itself was never approved and lives on almost entirely in the research-peptide and biohacking markets. Reported effects include faster, deeper tanning with less sun exposure, appetite suppression, and spontaneous erections in men. Reported downsides include nausea (especially on early doses), flushing, blood-pressure changes, and darkening or changing of existing moles — which is why dermatologic monitoring is repeatedly emphasized in the literature.

Mechanism of Action

Non-selective agonist at melanocortin receptors (MC1R for pigmentation, MC4R for sexual function and appetite). MC1R activation increases eumelanin synthesis; MC4R activation in the hypothalamus drives erectile response and reduces appetite.

Use Cases

✓Skin tanning with reduced UV exposure
✓Libido and erectile function
✓Appetite suppression (secondary)

Research Summary

Early clinical work at the University of Arizona explored melanocortin agonists for photoprotection and sexual dysfunction; that program led to the approved drug bremelanotide (PT-141). Melanotan II itself was never approved and remains research-only, with case reports of nausea, blood-pressure changes, and darkening or changing moles.

Explain It Like I'm 5 Years Old

Your skin has little factories that make the brown color that shows up when you tan. Melanotan II is like a manager who walks into those factories and tells them to work much harder, so you get tan with a lot less time in the sun. It also flips a switch in the brain that affects hunger and attraction, which is why people notice more than just a tan.

How the Gym Bros Are Using It

The classic pre-summer stack for lifters who want to look shredded and dark on stage or at the beach without frying in a tanning bed. Small starter doses (0.25 mg) to build tolerance and avoid the nausea, then micro-doses to maintain the tan. The libido bump is a well-known bonus. Two big cautions the community actually respects: watch your moles closely (get anything new or changing checked), and expect some nausea and facial flushing early on. Not a performance peptide — purely aesthetics and libido.

Typical Dosing

Research protocols: 0.25–1 mg subcutaneous, titrated slowly. Not a medical recommendation.

Administration

Subcutaneous injection

Research Chemical

Research use only, not FDA-approved. Linked to nausea, blood-pressure changes, and changes in moles/melanoma risk; dermatologic monitoring is advised in the literature.