What Is PT-141? Melanocortin Peptide Research Guide

An overview of PT-141 — bremelanotide — covering the melanocortin-4 pathway, its narrow approved medical use, and its research-use-only status in the UK.

7 min read · Published 2026-06-23

What Is PT-141?

PT-141 (international name bremelanotide) is a cyclic melanocortin-receptor agonist, structurally related to Melanotan-2, with activity at the melanocortin-4 receptor (MC4R).

Research use only. This material is supplied for in-vitro laboratory research. It is not a medicine and is not for human or veterinary consumption, administration, or therapeutic use.

How PT-141 Is Studied to Work

In research PT-141 is associated with central melanocortin-4 receptor signalling. The MC4R pathway is studied in neuroscience and physiology, distinct from peripheral vascular mechanisms.

Approved Use & Regulatory Status

As bremelanotide (brand Vyleesi), this molecule is FDA-approved in the US for a specific indication (hypoactive sexual desire disorder in certain adults) under medical supervision. It does not hold a UK marketing authorisation for general use. Research-grade 'PT-141' is not the approved product and is supplied for laboratory research only — not for human use.

Research Handling & Quality

As a lyophilised (freeze-dried) peptide it is typically stored frozen and reconstituted with bacteriostatic water for in-vitro work — see our reconstitution guide and storage guide. Identity and purity should be verified against a batch-matched Certificate of Analysis (COA) with HPLC and mass-spectrometry data. View pt-141 product details and COA.

Frequently Asked Questions

Is PT-141 approved in the UK?

The related medicine bremelanotide (Vyleesi) is FDA-approved in the US for a specific indication, but research-grade PT-141 has no UK authorisation and is for laboratory use only.

What receptor does PT-141 act on?

It is studied as a melanocortin-4 receptor (MC4R) agonist.

Is PT-141 the same as Melanotan-2?

They are structurally related melanocortin agonists, but PT-141 (bremelanotide) is a distinct molecule with its own approved medical form (Vyleesi).

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