Melanotan II · research summary

Five primary melanomas in situ in a patient with recent tanning bed use, melanotan exposure, and anabolic hormone use.

JAAD case reports · 2026. Summary drawn from the study's full text. Each statement is followed by the exact sentence it comes from. This is a research summary, not medical advice.

Study type

Case report
“We present a case of multiple primary melanomas in situ arising in preexisting nevi that underwent reported darkening following melanotan exposure.”

Subjects

49-year-old White male with Fitzpatrick skin phototype II
“A 49-year-old White male with Fitzpatrick skin phototype II presented for evaluation of multiple clinically atypical pigmented lesions on the trunk.”

Sample size

1 patient
“We present a case of multiple primary melanomas in situ arising in preexisting nevi that underwent reported darkening following melanotan exposure.”

Duration

Approximately 2-3 weeks from initiation of exposure to biopsy
“After approximately 2-3 weeks of combined melanotan exposure and tanning bed use, he presented for evaluation of multiple clinically atypical pigmented lesions, and biopsies were performed on January 7, 2026.”

Reported findings

Histopathologic examination demonstrated melanoma in situ arising in severely dysplastic nevi in all 5 biopsied specimens.
“Histopathologic examination demonstrated melanoma in situ arising in severely dysplastic nevi in all 5 specimens.”
The patient reported rapid darkening of multiple preexisting nevi within approximately 1 week of initiating melanotan.
“Within approximately 1 week of initiating melanotan, he noted rapid darkening of multiple preexisting nevi, describing that several lesions “turned black.””
Immunohistochemical staining with SOX-10 highlighted junctional melanocytes, and PRAME immunoreactivity was detected in a subset of atypical melanocytes.
“Immunohistochemical staining with SOX-10 highlighted junctional melanocytes, and PRAME immunoreactivity was detected in a subset of atypical melanocytes.”

Limitations stated by the authors

Causality cannot be established from a single observational case, exposure history was based on self-report without independent verification, and tanning bed use is a major confounding variable.
“Causality between melanotan exposure and melanoma development cannot be established from a single observational case.”

Source: PubMed 42328529 · DOI 10.1016/j.jdcr.2026.05.009 · all study summaries

Reported findings

Histopathologic examination demonstrated melanoma in situ arising in severely dysplastic nevi in all 5 biopsied specimens.

“Histopathologic examination demonstrated melanoma in situ arising in severely dysplastic nevi in all 5 specimens.”

The patient reported rapid darkening of multiple preexisting nevi within approximately 1 week of initiating melanotan.

“Within approximately 1 week of initiating melanotan, he noted rapid darkening of multiple preexisting nevi, describing that several lesions “turned black.””

Immunohistochemical staining with SOX-10 highlighted junctional melanocytes, and PRAME immunoreactivity was detected in a subset of atypical melanocytes.

“Immunohistochemical staining with SOX-10 highlighted junctional melanocytes, and PRAME immunoreactivity was detected in a subset of atypical melanocytes.”

Limitations stated by the authors

Causality cannot be established from a single observational case, exposure history was based on self-report without independent verification, and tanning bed use is a major confounding variable.

“Causality between melanotan exposure and melanoma development cannot be established from a single observational case.”