PT-141 (Bremelanotide) is a cyclic heptapeptide melanocortin-4 receptor agonist derived from the tanning peptide Melanotan II. It has actual FDA approval (as Vyleesi) for premenopausal hypoactive sexual desire disorder, which makes it unusual among informally-used peptides.
Important: it causes transient increases in blood pressure and heart rate, and is contraindicated with uncontrolled hypertension and cardiovascular disease. Nasal spray variants sold online are not pharmaceutical grade.
This entry is informational only and is not a recommendation.