PT-141, also designated bremelanotide, is a synthetic cyclic heptapeptide and melanocortin receptor agonist. It is a metabolite-derived analog of Melanotan II, differing by the substitution of a carboxyl group for the C-terminal amide — a change that markedly alters its receptor selectivity profile and largely removes the pigmentary activity of the parent compound.
Researchers investigate PT-141 as a tool for dissecting melanocortin receptor pharmacology. The melanocortin family spans five receptor subtypes with distinct tissue distributions and functions, and selective or partially selective agonists are essential to separating their contributions in experimental systems.
Solas Science supplies PT-141 as a research-grade compound in a metered nasal spray format at a labeled 100 mcg per spray, prepared under controlled conditions with quality procedures designed to support consistency, reliability, and analytical reproducibility.
For laboratory research use only. Not for human or veterinary use. Not a dietary supplement, food, drug, or cosmetic. Not for diagnostic or therapeutic application.
What Is PT-141?
PT-141 (CAS 189691-06-3) has the molecular formula C50H68N14O10 and a molecular weight of 1025.18 g/mol. Its structure is a lactam-bridged cyclic heptapeptide, Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, built around the His-D-Phe-Arg-Trp core that melanocortin agonists share.
Cyclization is what distinguishes this scaffold experimentally. Constraining the peptide backbone into a ring restricts its conformational freedom, which both increases receptor affinity and confers resistance to enzymatic degradation compared with a linear sequence of the same residues.
Published characterization describes PT-141 as an agonist at melanocortin receptors with activity reported principally at MC1R, MC3R and MC4R, and with substantially reduced activity at the receptor subtype responsible for melanogenesis relative to Melanotan II. The MC4R component is the focus of most current research interest, given that receptor’s role in central nervous system signaling.
About the Metered Nasal Spray Format
This preparation supplies PT-141 as an aqueous solution in a 10 mL bottle fitted with a metered pump delivering a labeled 100 mcg per actuation — approximately 100 metered sprays per bottle, or 10 mg of compound in total. Actual spray count varies with pump priming and residual volume.
The intranasal format has a specific place in the PT-141 research record: the compound was originally developed and characterized as an intranasal preparation before later work moved to other routes. Studies replicating or comparing against that earlier body of work therefore often specify a metered nasal preparation.
Researchers who need to control concentration themselves, or who are working in cell culture and solution-phase assays, may prefer the lyophilized powder presentation, which is reconstituted to a concentration of the investigator’s choosing. This metered format trades that flexibility for a fixed, pre-measured dose delivered without reconstitution.
Scientific Research Areas of PT-141
PT-141 is investigated across receptor pharmacology, neuroendocrinology, and peptide structure-activity research.
Melanocortin Receptor Pharmacology
The primary research application involves receptor characterization. Investigators examine:
- Binding affinity and functional potency across MC1R through MC5R
- cAMP accumulation and G-protein coupling in receptor-expressing cell lines
- Agonist, partial agonist, and biased signaling behavior
- Selectivity comparison against α-MSH and Melanotan II
Central Nervous System Signaling Research
Because MC4R is expressed throughout the central nervous system, preclinical work explores:
- Hypothalamic signaling and neuronal activation mapping
- Downstream dopaminergic and oxytocinergic pathway interaction
- Behavioral endpoints in standardized rodent paradigms
- Receptor expression and distribution studies
Peptide Structure-Activity Research
As a cyclized analog of a linear parent compound, PT-141 supports work on:
- Conformational constraint and receptor affinity relationships
- Lactam bridge chemistry and cyclization strategy
- Enzymatic stability of cyclic versus linear peptides
- Effect of C-terminal modification on subtype selectivity
Metabolic and Peripheral Melanocortin Research
Broader melanocortin research using PT-141 examines:
- MC3R and MC4R contributions to energy balance in preclinical models
- Peripheral vascular and inflammatory melanocortin signaling
- MC1R-mediated endpoints in pigment cell culture
- Cross-talk between melanocortin subtypes in intact tissue
Product Specifications
- Compound: PT-141 (bremelanotide)
- Format: Metered nasal spray bottle
- Labeled strength: 100 mcg per spray
- Total volume: 10 mL
- Sprays per bottle: Approximately 100
- Total compound content: 10 mg
- Intended use: Laboratory and analytical research applications only
Quality and Analytical Testing
PT-141 supplied by Solas Science is prepared under controlled conditions and evaluated through quality procedures designed to support purity, consistency, and reliability for laboratory and analytical research applications.
Quality processes may include:
- Raw material assessment
- Compound identity confirmation
- Purity evaluation
- Batch consistency testing
- Fill-volume and concentration verification
- Controlled preparation environments
- Laboratory-grade metered-spray packaging
Analytical documentation for the current lot is available on request.
Product Information
| Specification | Details |
| Product Name | PT-141 Research Compound |
| Brand | Solasscience |
| Chemical Name | Acetyl-L-norleucyl-cyclo[L-α-aspartyl-L-histidyl-D-phenylalanyl-L-arginyl-L-tryptophyl-L-lysyl] |
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Molecular Formula | C50H68N14O10 |
| Molecular Weight | 1025.18 g/mol |
| CAS Number | 189691-06-3 |
| Format | Metered nasal spray, 10 mL bottle |
| Labeled Strength | 100 mcg per spray |
| Total Content | 10 mg |
| Formulation | Aqueous solution |
| Compound Type | Cyclic heptapeptide melanocortin receptor agonist |
| Application | Laboratory and analytical research only |
| Research Area | Melanocortin receptor signaling |
| Quality Standard | Research grade |
Handling and Storage
Store refrigerated at 2–8 °C, protected from light, and do not freeze — freeze-thaw cycling can degrade peptides in solution and damage the metering pump. Keep the bottle upright with the cap fitted, and clearly labeled for laboratory inventory. As an aqueous preparation this product has a shorter working life than a lyophilized powder; record the date the bottle is first opened and handle it accordingly.
Handle in accordance with standard laboratory safety practice, including appropriate personal protective equipment. The metering pump is intended for controlled dispensing in a laboratory setting only. Keep out of reach of children and unauthorized personnel.
Research Use Disclaimer
This product is sold strictly for laboratory research use only. It is not intended for human consumption, human ingestion, intranasal administration to humans or animals, veterinary use, therapeutic use, diagnostic use, or any in-vivo application. It is not a dietary supplement, food, drug, or cosmetic, and it has not been evaluated by the FDA for safety or efficacy. The metered-spray format is a laboratory dispensing convenience and is not a route-of-administration recommendation. No statement on this page should be interpreted as a medical claim or as a recommendation for personal use.
By purchasing this product, the buyer confirms they are a qualified researcher or research organization, that they are at least 21 years of age, and that the material will be handled and used only within an appropriate research setting in compliance with all applicable local, state, and federal laws and regulations.
