PT-141 (Bremelanotide) Research Guide: Melanocortin-Receptor Mechanisms and Research Findings

For Research Use Only. This guide is provided strictly for in-vitro laboratory and educational purposes for qualified researchers. It describes molecular and mechanistic research only, is not medical advice, and refers to no product intended for human or veterinary use, diagnosis, or treatment. Not evaluated by the FDA.

PT-141 (Bremelanotide) is a cyclic melanocortin-agonist peptide used as a reference probe of central melanocortin-receptor signaling. This expanded guide covers its structure, receptor mechanism, and research context.

Molecular identity & structure

PT-141 is a synthetic cyclic heptapeptide and the deaminated metabolite of the melanocortin agonist Melanotan II. Its cyclic structure confers stability and receptor affinity across the melanocortin family.

Mechanism of action (in vitro)

PT-141 is an agonist of melanocortin receptors, with research interest centered on the MC4 receptor (and activity at MC1R). These are class A GPCRs coupling to Gαs; agonism raises cAMP and activates PKA in receptor-expressing cells, placing PT-141 within central melanocortin-signaling models.

Downstream signaling

MC4R is a key node in central melanocortin circuitry, and PT-141 is used to probe cAMP-dependent signaling and receptor pharmacology at this node in vitro, including selectivity across MC1R–MC5R subtypes.

Preclinical research landscape

PT-141 is studied in melanocortin-receptor binding and cAMP reporter assays and preclinical neuroendocrine models. Findings characterize receptor signaling in these systems and are not indicators of any human outcome.

Related compounds

Compare with the parent agonist Melanotan II and the melanocortin fragment KPV, which engage overlapping receptor subtypes.

Laboratory handling & reconstitution

Lyophilized peptide is solubilized by adding bacteriostatic or sterile water slowly down the vial wall and swirling gently — never shaking. Lyophilized material is stored at −20 °C protected from light; reconstituted material is held at 2–8 °C for short-term laboratory use, with single-use aliquots to limit freeze–thaw degradation. See the reconstitution calculator for solvent-to-concentration reference.

Analytical characterization

Research-grade reference material should carry a batch-specific Certificate of Analysis: reverse-phase HPLC for chromatographic purity (commonly ≥98%) with a chromatogram, mass spectrometry confirming molecular identity against the theoretical mass, and the name of the independent testing laboratory. Batch records appear on our Lab Reports page.

Research applications

Uses include melanocortin-receptor binding and cAMP signaling assays, MC-subtype selectivity studies, and comparative melanocortin pharmacology.

Research Use Only — not for human or veterinary use, diagnosis, or treatment. Purchases are restricted to qualified researchers.