Melanotan II
Also known as: MT-2, MT-II
A synthetic melanocortin peptide originally developed at the University of Arizona for skin tanning. It also causes sexual arousal as a side effect. It is not approved by any regulatory agency and carries significant safety concerns.
How it works
Melanotan II is a non-selective melanocortin receptor agonist, meaning it activates multiple melanocortin receptors at once. It stimulates MC1R receptors in skin cells to produce more melanin (darker skin pigment), while also activating MC3R and MC4R receptors in the brain that affect sexual arousal and appetite. Because it crosses the blood-brain barrier and hits many receptors, it has a wide range of effects and side effects.
Common uses
- Skin tanning (unapproved)
- Sexual arousal and erectile function (unapproved)
- Appetite suppression (unapproved)
Side effects
- Nausea and facial flushing (very common)
- Spontaneous and prolonged erections (priapism) in men
- Loss of appetite
- Fatigue and yawning
- Darkening of existing moles
- Rare but serious: kidney damage (renal infarction), rhabdomyolysis
- Possible increased melanoma risk from mole changes
Key research
- University of Arizona studies showed potent tanning effects and sexual arousal in human subjects
- At least 5 case reports of melanoma during or after Melanotan II use, though UV exposure may be the primary risk factor
- 2021 review concluded melanoma risk is likely tied to increased UV exposure in tanning-seeking users rather than the peptide itself
Safety notes
- Expected to remain on FDA Category 2 (restricted) in 2026 due to melanoma and cardiovascular concerns
- Not approved for any use in any country
- The safer, selective version (afamelanotide/Melanotan I) is FDA-approved as Scenesse for erythropoietic protoporphyria
- Black market products often have unknown purity and contamination
- Cleveland Clinic and other health organizations have warned against its use
Too many clinics, not enough clarity?
We don't sell peptides. Tell us your goals and we'll connect you with a vetted provider who can figure out what actually makes sense for you.
See what's right for youExplore other peptides
Semaglutide
An FDA-approved GLP-1 receptor agonist used for type 2 diabetes and chronic weight management. One of the most well-studied peptides available.
Tirzepatide
A dual GIP/GLP-1 receptor agonist that has shown even greater weight loss results than semaglutide in head-to-head trials.
BPC-157
A synthetic peptide derived from human gastric juice, studied primarily in animal models for its regenerative and anti-inflammatory properties. Not FDA-approved.
CJC-1295 / Ipamorelin
A commonly paired combination of growth hormone-releasing peptides used to stimulate natural GH production for anti-aging, body composition, and recovery.