PT-141: 10 mg ($25)
Overview
PT-141, generic name bremelanotide, is a cyclic peptide acting on the melanocortin receptor family. What distinguishes it pharmacologically is where it acts: drugs such as sildenafil and tadalafil work peripherally on vascular tissue, while PT-141 binds receptors in the central nervous system. The proposed link is that it boosts dopamine in brain areas tied to sexual motivation and desire. It is an FDA-approved prescription pharmaceutical, marketed as Vyleesi.
In plain terms
The melanocortin system is a set of receptors distributed across quite different tissues — some in skin, some in the brain, some in the immune system — that all respond to a related family of signaling peptides. Because the same signal reaches such different destinations, molecules in this family tend to have effects spanning several unrelated systems at once.
PT-141 came out of research on a different melanocortin compound and was found to act primarily on receptors in the central nervous system rather than in skin. That central action is what distinguished it and led to its eventual pharmaceutical development. Its scientific interest lies in receptor selectivity: the melanocortin receptors are closely related to one another, so designing a molecule that engages some and not others is a demanding structural problem, and PT-141 is a well-characterized case study in it.
Technical description
Bremelanotide is a synthetic cyclic heptapeptide analogue derived from α-melanocyte stimulating hormone, developed as an active metabolite of melanotan II. Cyclization via a lactam bridge confers conformational rigidity and metabolic stability relative to linear analogues.
It functions as a non-selective melanocortin receptor agonist with principal activity at MC4R and MC3R, class A GPCRs signaling through Gs and adenylyl cyclase. MC4R is expressed predominantly in central nervous system tissue, and central rather than peripheral receptor engagement is considered the basis of its pharmacological profile. Residual activity at MC1R accounts for reported pigmentary effects. Administration in the approved product is subcutaneous, reflecting negligible oral bioavailability.
- Full name
- Bremelanotide
- Synonyms
- PT-141, Vyleesi (brand)
- CAS number
- 189691-06-3
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- Sequence
- Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
- Receptor targets
- MC4R, MC3R (agonist); residual MC1R
- Appearance
- White lyophilized powder
- Storage
- Lyophilized: −20 °C, protected from light. Reconstituted: 2–8 °C.
Regulatory status
Bremelanotide is an FDA-approved prescription pharmaceutical marketed as Vyleesi, approved in 2019 for a specific indication and dispensed under prescription. Approved status applies to the pharmaceutical product manufactured and released under cGMP with regulatory oversight. Material supplied for laboratory research is a separate article, is not the approved drug product, and is not manufactured, tested, or released under pharmaceutical standards.