Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report What Is Melanotan, the So Called Barbie Peptide? PS Beauty Melanotan is BACK! After recent regulatory changes, compounding pharmacies are once again able to produce Melanotan peptide! If you've been missing the benefits of this popular peptide, now's your chance Melanotan is not a tan. It's an unregulated peptide with real risk. As a dermatologist, here's the reality: It has been linked to new and changing moles including cases of