What is PT-141?
PT-141 is a cyclic heptapeptide (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, 1,025.2 g/mol, CAS 189691-06-3). It differs from melanotan II only at the chain end, a free acid instead of an amide, which shifts its action away from skin pigmentation towards central melanocortin signalling.
Research status
Bremelanotide was studied in two phase 3 trials (RECONNECT) in premenopausal women with low sexual desire and produced small improvements over placebo, acting through brain receptors rather than blood flow. The most common side effect was nausea, followed by flushing, headache and a transient rise in blood pressure; repeated use caused hyperpigmentation.
Status
Approved in the US as Vyleesi since 2019; not approved in the EU. Research use only. The related peptide is melanotan 2.
Background in the magazine: Melanotan 2, melanotan 1 and PT-141 explained
