There are two peptides people talk about for tanning: Melanotan 1 and Melanotan 2. Melanotan 1 works slower and mainly targets the skin, leading to a more gradual and even increase in Metastatic Malignant Peripheral Nerve Sheath Tumor With NF1 Successfully Treated With 'Gradual Subtraction' ICE Chemotherapy Anticancer Research Melanotan II Wikipedia Brain metastases as primary manifestation of a melanocytic malignant peripheral nerve sheath tumor in a 60 year old man BMC Neurology Springer Nature Link