What Is PT-141/Bremelanotide?
PT-141, also known as Bremelanotide (CAS 32780-32-8), is a synthetic cyclic heptapeptide melanocortin receptor agonist with the amino acid sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH. It has a molecular weight of 1025.18 Da and molecular formula C50H68N14O10. PT-141 was derived from Melanotan II through metabolic conversion studies, where it was identified as the primary active metabolite responsible for the central nervous system effects of its parent compound.
The key structural difference between PT-141 and Melanotan II is the C-terminal modification: PT-141 has a free carboxylic acid (OH) terminus rather than the amide (NH2) terminus of Melanotan II. This modification shifts the receptor selectivity profile, reducing MC1R-mediated melanogenic activity while preserving MC3R and MC4R agonism. This receptor preference makes PT-141 a more targeted tool for studying central melanocortin pathways without the confounding pigmentation effects of Melanotan II.
PT-141 is classified within the melanocortin peptide category and has one of the most advanced clinical development histories of any peptide in our catalog. It is supplied for research use only (RUO) through our wholesale peptide program.
Mechanism of Action
PT-141/Bremelanotide exerts its pharmacological effects primarily through agonism of melanocortin receptors MC3R and MC4R in the central nervous system. Both receptors are G protein-coupled receptors that signal through Gs/cAMP and Gq/phospholipase C pathways. MC3R and MC4R are densely expressed in hypothalamic nuclei, the medial preoptic area, the paraventricular nucleus, and other brain regions implicated in sexual function, energy homeostasis, and autonomic regulation.
The sexual function pathway studied most extensively with PT-141 involves MC4R activation in the medial preoptic area and paraventricular nucleus, which triggers downstream activation of oxytocinergic neurons projecting to spinal cord autonomic centers. This central mechanism distinguishes PT-141 from peripherally acting compounds and accounts for its studied effects on both physiological and motivational components of sexual response in animal models.
PT-141 retains partial MC1R activity but at significantly lower potency than Melanotan II, which explains the reduced melanogenic effects observed in comparative studies. The compound also shows activity at MC5R, though the physiological relevance of this interaction in the context of sexual function research is less well characterized. Researchers studying melanocortin receptor pharmacology frequently compare PT-141 with Melanotan II for receptor selectivity profiling and with centrally active peptides like Selank for CNS pathway mapping studies.
Research Applications
PT-141/Bremelanotide has been investigated across sexual medicine, neuroscience, and melanocortin pharmacology research:
Sexual Function Research
The primary research application for PT-141 involves its effects on sexual motivation and physiological sexual response. In preclinical models, researchers have studied PT-141 in both male and female animal paradigms, documenting effects on lordosis behavior (female rodents), mounting behavior, and erectile function (male rodents). These behavioral endpoints provide mechanistic evidence for centrally mediated sexual function modulation through the melanocortin system. PT-141 has also been investigated in published clinical trials, making it one of the most extensively characterized research peptides in the sexual medicine domain.
Melanocortin Receptor Pharmacology
As a moderately selective MC3R/MC4R agonist, PT-141 serves as an important pharmacological tool in receptor characterization studies. Researchers use it in competitive binding assays, functional cAMP and inositol phosphate assays, and receptor internalization studies to map melanocortin receptor signaling. Its distinct selectivity profile relative to Melanotan II enables delineation of receptor subtype contributions to specific physiological effects.
Hypothalamic Circuit Research
Neuroscience researchers have used PT-141 to investigate melanocortin signaling in hypothalamic circuits. Studies employing c-Fos immunohistochemistry, electrophysiology, and optogenetic approaches have mapped the neuronal populations activated by PT-141 in the medial preoptic area, paraventricular nucleus, and arcuate nucleus. These studies contribute to understanding the central neural substrates of motivated behaviors.
Energy Balance and Appetite
Through its MC3R/MC4R activity, PT-141 has been investigated for effects on food intake and energy expenditure in rodent models. While its primary research focus is sexual function, the shared receptor pharmacology with appetite-regulating pathways makes PT-141 relevant to comparative studies with metabolic melanocortin agonists. Related weight management compounds target overlapping central pathways.
For bulk supply supporting clinical-grade and large-scale preclinical research, visit the PT-141 wholesale pricing page.
Available Formats and Bulk Options
PT-141/Bremelanotide is available from Wholesale Bulk Peptides in multiple formats:
- 5 mg lyophilized vials — suited for receptor binding assays, functional assays, and pilot behavioral studies
- 10 mg lyophilized vials — optimized for chronic dosing protocols and multi-arm preclinical studies
- Bulk lyophilized powder — gram-scale quantities for contract research organizations, peptide resellers, and private-label peptide brands
Custom vial sizes and packaging configurations available for qualified accounts. Apply through the wholesale program application.
Wholesale Pricing Summary
PT-141/Bremelanotide wholesale pricing is volume-tiered for B2B buyers, research institutions, and peptide resellers. Pricing scales favorably at higher volume commitments. For complete pricing, MOQs, and delivery schedules, visit the PT-141 wholesale page. New accounts apply through the wholesale program portal.
Quality Assurance, Testing, and COAs
Every batch of PT-141/Bremelanotide undergoes comprehensive analytical testing:
- HPLC — confirms purity of 98% or greater with chromatographic verification of cyclic lactam structure
- Mass Spectrometry — validates the 1025.18 Da molecular weight and differentiates from Melanotan II (1024.18 Da amide)
- Amino Acid Analysis — quantifies residue composition including the D-Phe stereoisomer
- Endotoxin Testing (LAL) — ensures suitability for in vivo behavioral and pharmacological research
Batch-specific COAs accompany every shipment. Access our COA library and testing methodology page for full details. The Peptide COA Guide assists with analytical interpretation.
Storage and Stability
Store PT-141/Bremelanotide lyophilized powder at -20 degrees Celsius, protected from light and moisture. The cyclic structure provides good stability, with a shelf life exceeding 24 months under recommended conditions. Reconstitute with bacteriostatic water or sterile saline and store at 2-8 degrees Celsius for use within 30 days. Like Melanotan II, the tryptophan residue is photosensitive; minimize light exposure during handling. Aliquot reconstituted material into single-use volumes to prevent degradation from repeated freeze-thaw cycles.
Compliance and Intended Use
PT-141/Bremelanotide is supplied by Wholesale Bulk Peptides for research use only (RUO). It is not sold as a drug, dietary supplement, food additive, or cosmetic product. While Bremelanotide has been the subject of advanced clinical development, the material distributed through our wholesale program is intended exclusively for qualified laboratory research. Purchasers must comply with all applicable federal, state, and institutional regulations, and maintain clear RUO labeling on all downstream products.
Related Compounds
Researchers studying PT-141/Bremelanotide frequently investigate related melanocortin and neuropeptide compounds:
- Melanotan II — the parent compound and non-selective MC1R-MC5R agonist, essential for receptor selectivity comparison studies
- KPV — the C-terminal alpha-MSH tripeptide with anti-inflammatory MC1R-pathway activity and minimal melanogenic effects
- Selank — a nootropic heptapeptide studied for CNS effects including anxiolytic activity, useful for comparative neuropeptide pathway studies
- Epitalon — a neuroendocrine-active tetrapeptide studied for pineal gland modulation and telomerase activation
Browse the complete melanocortin peptide catalog. For brand-building opportunities, visit our Start a Peptide Brand resource.
Frequently Asked Questions About PT-141/Bremelanotide
Our wholesale support team addresses frequently asked questions from buyers about PT-141/Bremelanotide covering analytical differentiation from Melanotan II, reconstitution and dosing references from published literature, stability data, and regulatory classification questions. For product-specific FAQs, see the PT-141 wholesale page. For general questions, visit the wholesale peptides hub.
Disclaimer: This material is provided for informational and research purposes only. PT-141/Bremelanotide is sold as a Research Use Only (RUO) compound. It is not intended for human or veterinary diagnostic or therapeutic use. All buyers are responsible for ensuring compliance with applicable laws and institutional guidelines. Wholesale Bulk Peptides makes no claims regarding the safety or efficacy of this compound for any purpose other than qualified laboratory research.