Subcutaneous Melanotan II Injection Caused Acute Ischemic Priapism Requiring Surgical Decompression

Melanotan II is a synthetic analog of the naturally occurring peptide hormone α-melanocyte-stimulating hormone. It is illicitly sold online for its ability to induce skin tanning without sun exposure by stimulating melanocytes. Beyond its cosmetic use, it is also leveraged in unlicensed clinics as a sexual stimulant and has been formally investigated as a potential treatment for erectile dysfunction. Standard management for acute ischemic priapism, a painful and persistent erection lasting more than four hours without sexual stimulation, involves a stepwise approach starting with conservative measures. These include cavernosal aspiration, irrigation, and the injection of sympathomimetic drugs like phenylephrine. When these first-line treatments fail, the condition becomes refractory, posing a significant risk of permanent erectile tissue damage and subsequent dysfunction, necessitating more invasive surgical interventions.

This case report documents the clinical course of a single male patient who presented to the emergency department with acute ischemic priapism. The patient's condition developed after a subcutaneous injection of Melanotan II. The initial management strategy followed standard protocols: clinicians attempted to resolve the priapism using cavernosal aspiration and irrigation, followed by intracavernous injections of phenylephrine. The primary endpoint was the achievement of detumescence (the return of the penis to a flaccid state). The failure of these initial, less invasive methods defined the condition as refractory.

The patient's priapism did not resolve with first-line medical management. Both cavernosal aspiration/irrigation and intracavernous phenylephrine injection failed to achieve detumescence. This lack of response necessitated escalation to surgical intervention. The patient underwent an operative procedure known as penoscrotal decompression, described as a promising alternative technique for managing refractory ischemic priapism. The surgery was successful in resolving the condition. The authors note that this is a rare adverse event, with priapism following Melanotan II injection having been reported in the literature only twice before this case.

The case highlights a rare but severe complication of illicit Melanotan II use, where the resulting ischemic priapism was refractory to standard medical interventions and required surgical management.