Peptide · Research Monograph · Cyclic heptapeptide alpha-MSH analog (MC3R/MC4R agonist)

PT-141

Melanocortin Arousal Studies

PT-141 is also called bremelanotide. It is a ring-shaped peptide that binds two melanocortin receptors, MC3R and MC4R. Research has measured its activity in the central nervous system rather than in blood vessels, which separates it from other compounds studied in the same area. Its structure comes from Melanotan II, which breaks down into a nearly identical molecule.

For laboratory research use only - not for human or animal use

Available in the Eon catalog - PT-141 from $45.00 Certificate of analysis (PDF)

Molecular data

Molecular formulaC50H68N14O10
Molecular weight1025.18 Da
SequenceAc-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
Sequence length7 residues
CAS / identifierBremelanotide
Physical formLyophilized powder
Available sizes10mg

How it works

MC4R Agonism

Melanocortin-4 Receptor Activation

PT-141 (bremelanotide) acts as a non-selective melanocortin receptor agonist with high affinity for MC3R and MC4R. Activation of MC4R in the central nervous system is associated with the compound's observed effects on arousal pathways in preclinical and clinical research.

  • High-affinity binding at MC3R and MC4R
  • Central nervous system activity via hypothalamic pathways
  • Distinct mechanism from PDE5 inhibitors (no vascular action)
Central Pathways

Hypothalamic Signaling Modulation

Research reports PT-141 acts centrally through hypothalamic and limbic system circuits, influencing dopaminergic and serotonergic pathways. This central mechanism of action distinguishes it from peripherally-acting compounds and underlies the approved indication for the bremelanotide pharmaceutical, Vyleesi.

  • Modulates dopaminergic neurotransmission
  • Acts on hypothalamic arousal circuits
  • Distinct from peripheral vascular mechanisms
Alpha-MSH Analog

Cyclic MSH Derivative

PT-141 is a synthetic cyclic analog of alpha-melanocyte stimulating hormone (α-MSH). Its cyclic structure carries greater metabolic stability and narrower receptor selectivity than its linear precursor. The compound is derived from Melanotan II via hydrolysis of the cyclic lactam ring.

  • Cyclic structure raises metabolic stability
  • Derived from Melanotan II via chemical modification
  • Narrower selectivity profile vs. linear α-MSH

What the research shows

Melanocortin Signalling

Central Arousal Models

Bremelanotide is the research designation for the compound marketed as Vyleesi. Melanocortin-pathway signalling in sexual-function models is the focus of research on this compound.

Receptor Pharmacology

Melanocortin System

Research into MC3R and MC4R signaling cascades, including downstream cAMP production and modulation of hypothalamic neuropeptide systems involved in energy homeostasis and arousal.

Sexual Function Models

MC4R Pathway Models

Central MC4R signalling is studied as a pathway distinct from the NO/cGMP cascade in sexual-function models.

Neuropharmacology

CNS Mechanism Studies

Investigation of central nervous system melanocortin receptor distribution, downstream signaling via Gs-coupled cAMP pathways, and interaction with dopaminergic reward circuitry in preclinical models.

Specification

Chemical NameBremelanotide
SequenceAc-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
Molecular Weight1025.18 Da
Molecular FormulaC₅₀H₆₈N₁₄O₁₀
FormLyophilized powder
Purity≥99% (HPLC verified)
TestingThird-party HPLC, Mass Spec, Endotoxin
Storage-20°C for long-term stability
SolubilityWater or bacteriostatic water
COAIncluded with every order

Frequently asked questions

What is PT-141 (Bremelanotide)?

PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide and analog of alpha-melanocyte stimulating hormone (α-MSH). It acts as an agonist at melanocortin receptors, particularly MC3R and MC4R. The compound was developed from Melanotan II and later approved by the FDA as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women.

How does PT-141 differ from PDE5 inhibitors like sildenafil?

PT-141 has a different mechanism from PDE5 inhibitors (like Viagra/Cialis). PDE5 inhibitors act peripherally on blood flow via the nitric oxide/cGMP pathway. PT-141 acts centrally at melanocortin receptors in hypothalamic and limbic circuits, with dopaminergic neurotransmission as the studied pathway rather than vascular mechanisms.

Is PT-141 FDA approved?

Bremelanotide (the pharmaceutical formulation, Vyleesi) is FDA-approved as of June 2019 for treating HSDD in premenopausal women. Research-grade PT-141 sold here is not the approved pharmaceutical formulation and is intended solely for in vitro research purposes. It should not be used therapeutically.

What receptors does PT-141 bind to?

PT-141 binds to multiple melanocortin receptor subtypes. It has highest affinity for MC4R and MC3R, with lower affinity for MC1R, MC2R, and MC5R. MC4R activation in the hypothalamus is believed to be the primary driver of its effects on arousal-related circuits based on receptor knockout studies and pharmacological profiling research.

How is bremelanotide characterised in melanocortin research?

Bremelanotide is a melanocortin receptor agonist with activity at MC4R, studied for central rather than vascular mechanisms of sexual-function signalling. This material is supplied for in vitro laboratory research only and is not offered for any human use.

How should research-grade PT-141 be stored?

Lyophilized PT-141 should be stored at -20°C for long-term stability and protected from light. Avoid repeated freeze-thaw cycles, which can degrade peptide integrity.

For laboratory research use only. Not a drug, supplement, or medical product; not for human or animal use. All findings referenced are from published preclinical/laboratory research.