https://en.wikipedia.org/wiki/Melanotan_II says it is banned in the United States, and anything you get on the black market isn't guaranteed to be pure.

BEWARE.

Melanotan is dangerous, sadly.

Tanning causes melanocyte production in your epidermis. Melanotan causes it throughout your body in an uncontrolled manner. In a wide variety of unrelated tissues.

It can lead to uncontrolled melanocyte production that doesn't shut off - cancer. Aggressive melanomas.

It disrupts normal hormone signalling which may downstream cause a variety of deleterious health effects and disease states.

There are also crazy reports of kidney failure, which may or may not be caused by the drug.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7148395/

https://pubmed.ncbi.nlm.nih.gov/23121206/

https://www.actasdermo.org/en-eruptive-dysplastic-nevi-follo...

I’m pretty sure Melanotan carries the risk of retinal pigmentation, or at least that was the case with the original. Not sure if II is different.