Question 1

How does Melanotan II differ from PT-141?

Accepted Answer

PT-141 (bremelanotide) is an MT-II analog developed by the same melanocortin research line. Bremelanotide went through phase 2 and 3 trials and is FDA-approved for hypoactive sexual desire disorder, with nausea (39.9%), flushing (20.4%) and headache (11%) as its most common side effects. MT-II itself never completed development and is not approved.

Question 2

Is Melanotan II safe for tanning?

Accepted Answer

Its safety for tanning has never been established. The only human trials were tiny phase I and erectile-dysfunction studies. Dermatology reviews describe changes in existing moles, new and sometimes dysplastic nevi, and several melanomas reported in users of unregulated melanotan, and note that national health agencies have issued safety warnings, although conclusive evidence of a causal link to melanoma is lacking.

Question 3

Can Melanotan II change moles?

Accepted Answer

Case reports say yes. A systematic review of eruptive melanocytic nevi found that drugs including melanotan were among the suspected triggers, and a review of unregulated α-MSH analogue use describes melanocytic changes in existing moles and new dysplastic nevi, plus four reported melanomas arising during or shortly after use. A 2025 case report described an oral mucosal melanoma in a young woman using MT-II nasal spray. Any new or changing mole needs a dermatologist's assessment.

Question 4

What side effects were seen in clinical studies?

Accepted Answer

In the 1996 phase I study, mild nausea occurred at most doses, along with a stretching-and-yawning complex, spontaneous erections lasting 1-5 hours, and somnolence and fatigue at the highest dose. In erectile-dysfunction trials, nausea and yawning were common, and 4 of 19 injections at 0.025 mg/kg caused severe nausea.

Question 5

Are there serious adverse events in users?

Accepted Answer

Case reports include low-flow priapism after melanotan injection, with erectile function not yet recovered four weeks later, and a renal infarction considered most likely due to MT-II; rhabdomyolysis and renal failure have also been described. Case reports cannot establish how often these occur.

Question 6

Is Melanotan II legal or approved?

Accepted Answer

It is not approved in the US. The FDA's page on bulk drug substances that may present significant safety risks in compounding names melanotan II among the substances withdrawn from its Category 2 list, and in the US it is a research-only compound. A UK case report notes it is unlicensed and its sale illegal in the United Kingdom.

Origin / Manufacturer	Synthetic
Form Factor	Lyophilized powder vial

Melanotan II

Specifications

Frequently Asked Questions

Sources & References