PT-141, also known as bremelanotide, is a synthetic peptide derived from the alpha-melanocyte-stimulating hormone (α-MSH). It is widely studied for its role in modulating melanocortin receptors, particularly those associated with neurological and physiological responses in laboratory research.

PT-141 (Bremelanotide): Research Overview

PT-141, also known as Bremelanotide, is a cyclic hepta-peptide melanocortin receptor agonist derived from Melanotan II. Unlike its parent compound which acts on all five melanocortin receptor subtypes, PT-141 demonstrates functional selectivity with primary activity at MC3R (melanocortin-3 receptor) and MC4R (melanocortin-4 receptor) — both of which are expressed in hypothalamic circuits governing sexual arousal, feeding behavior, and autonomic function. PT-141 does not act on peripheral vascular targets in the same manner as phosphodiesterase inhibitors, representing a distinct mechanistic class for sexual function research.

Key research findings include:

• MC4R-Mediated Arousal Pathway: MC4R activation in the medial preoptic area (mPOA) and paraventricular nucleus (PVN) of the hypothalamus stimulates dopaminergic and oxytocinergic signaling, driving central rather than peripheral mechanisms of arousal. (Wessells et al., 2000)
• Central vs. Peripheral Mechanism: PT-141's action is primarily central (CNS-mediated), distinguishing it from PDE5 inhibitors and making it an important research tool for studying central sexual function pathways.
• MC3R Energy Research: MC3R modulation has implications beyond sexual function — this receptor plays a role in energy homeostasis and feeding behavior, and PT-141's selectivity for MC3R provides a research tool for these pathways.
• Melanocortin System Research: The melanocortin system is implicated in diverse CNS functions including inflammation, nociception, and autonomic regulation — PT-141 serves as a selective probe for dissecting these pathways.

PT-141 research intersects with Kisspeptin in the reproductive neuroendocrine research space — Kisspeptin acts upstream at the GnRH/HPG axis level while PT-141 acts downstream on hypothalamic arousal circuits. For quality and purity considerations in receptor pharmacology research, see our Quality Control in Peptide Research guide.

Research Context: PT-141 in the Neuroendocrine and CNS Peptide Landscape

CNS neuropeptide research for reproductive and arousal biology spans multiple hormonal axes. PT-141 provides a selective melanocortin system research tool:

• PT-141 (Bremelanotide) — MC3R/MC4R agonist; central arousal pathway, hypothalamic dopamine/oxytocin modulation, distinct from vascular mechanisms
• Kisspeptin — KISS1R agonist; upstream HPG axis regulator, GnRH pulsatility, metabolic-reproductive coupling
• Epitalon — Pineal tetrapeptide; neuroendocrine aging, melatonin axis, reproductive aging context
• Pinealon — Pineal tripeptide; circadian, neuroprotective, and neuroendocrine research tools
• NAD+ — Metabolic coenzyme; neural energy metabolism supporting CNS peptide research contexts

Related Research Resources

• What Are Peptides: The Complete 2026 Research Guide
• How to Reconstitute Peptides Safely for R&D
• Quality Control in Peptide Research: Interpreting Purity
• Peptide Stacking Research Guide: Synergistic Combinations
• Peptide Safety 101: Finding the Safest Place to Buy Peptides

Key Properties

• Melanocortin Receptor Interaction: Investigated for its ability to bind and activate melanocortin receptors (MC1R through MC5R).
• Neurophysiological Modulation: Explored for its role in regulating central nervous system pathways in controlled research environments.
• Cellular Pathway Studies: Studied for its potential influence on cell signalling and receptor activation mechanisms.

Applications in Research

PT-141 is the focus of laboratory research investigating:

• Mechanisms of melanocortin receptor activation and neural pathway interactions.
• Potential effects on physiological responses related to receptor signalling.
• Cellular pathways that may be involved in systemic regulation and energy homeostasis.

Research is conducted in laboratories to expand understanding of PT-141’s biochemical interactions.

Storage and Handling Instructions

• Store PT-141 in its lyophilized form at -4°F (-20°C) or lower.
• Protect from light, moisture, and excessive heat to maintain stability.
• Discard unused or reconstituted solutions promptly in compliance with research protocols.

Safety Information

This product is intended for research purposes. You must:

• Follow institutional guidelines for handling and disposal.
• Use appropriate protective equipment.

Frequently Asked Questions

What is PT-141?
PT-141 is a synthetic peptide derived from α-MSH, studied for its role in activating melanocortin receptors and its potential effects on neural pathways.

How should PT-141 be stored?
Store PT-141 at -4°F (-20°C) in a sealed container protected from light and moisture. Reconstituted solutions should be used promptly following laboratory protocols.

What are the primary research focuses of PT-141?
Research explores its effects on melanocortin receptor activation, neural pathway modulation, and its systemic regulation mechanisms in laboratory settings.

Frequently Asked Questions

What is PT-141 and how is it classified in research?

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as an agonist at melanocortin receptors MC3R and MC4R, predominantly expressed in the central nervous system. In preclinical research models, it has been investigated for its centrally-mediated effects on autonomic and neuroendocrine pathways related to arousal physiology. All studies are conducted in controlled laboratory environments.

What is the mechanism of action of PT-141 in research models?

PT-141 activates MC3R and MC4R receptors in the hypothalamic and limbic regions of the central nervous system, modulating downstream signaling pathways in rodent behavioral models. Unlike PDE5 inhibitors which act peripherally, PT-141 acts through central melanocortin pathways. This distinct mechanism has been studied through receptor binding assays, in vitro cell signaling experiments, and rodent behavioral research models.

What is the molecular structure of PT-141?

PT-141 is a cyclic heptapeptide (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH) with a molecular weight of approximately 1,025 Da. The cyclic structure enhances stability and receptor selectivity compared to linear peptides. The D-phenylalanine substitution contributes to resistance against enzymatic degradation, making it a useful research tool for melanocortin receptor biology studies.

What purity standards are required for research-grade PT-141?

Research-grade PT-141 should demonstrate greater than or equal to 98% purity as confirmed by HPLC analysis, with cyclic peptide identity verified by mass spectrometry. Given the cyclic structure, identity verification beyond purity testing is recommended to confirm correct cyclization in each synthetic batch. In-house purity testing ensures batch consistency.

How should PT-141 be stored for laboratory research?

Lyophilized PT-141 should be stored at -20 degrees C or lower, protected from light and moisture. Reconstitution with sterile physiological saline is standard for research applications. Solutions should be used promptly per the experimental protocol and not stored long-term in reconstituted form to maintain structural integrity of the cyclic peptide.

What research areas have studied PT-141 beyond melanocortin receptor biology?

Published research has examined PT-141 in the context of central nervous system melanocortin signaling, neuroendocrine pathway research, and receptor pharmacology. Clinical research on bremelanotide (Vyleesi) led to FDA approval in 2019 for a specific indication under regulated conditions. Preclinical research continues to investigate melanocortin pathways in metabolic and autonomic function in controlled settings.

References

1. Molinoff PB, Shadiack AM, Earle D, Diamond LE, Quon CY. “PT-141: a melanocortin agonist for the treatment of sexual dysfunction.” Ann N Y Acad Sci. 2003;994:96-102.. PubMed
2. Hedlund P. “PT-141 Palatin.” Curr Opin Investig Drugs. 2004;5(4):456-62.. PubMed
3. Shadiack AM, Sharma SD, Earle DC, Spana C, Hallam TJ. “Melanocortins in the treatment of male and female sexual dysfunction.” Curr Top Med Chem. 2007;7(11):1137-44.. PubMed
4. Dhillon S, Keam SJ. “Bremelanotide: First Approval.” Drugs. 2019;79(14):1599-1606.. PubMed