In short: PT-141 (bremelanotide) is a cyclic heptapeptide derived from the α-MSH analogue Melanotan II, supplied by Vexar Lab strictly for in-vitro laboratory research and not approved for human consumption. It is a well-characterised tool compound for studying melanocortin-receptor signalling in pre-clinical models. Before ordering any peptide, research buyers should confirm purity of at least 99% by HPLC, identity confirmation by mass spectrometry, and clear batch numbering with a corresponding certificate of analysis (COA).
What is PT-141?
PT-141 is a cyclic seven-amino-acid peptide that acts as a melanocortin-receptor agonist, with reported selectivity for the MC3 and MC4 receptor subtypes. It originated from work on α-melanocyte-stimulating hormone analogues at the University of Arizona, where Melanotan II was developed; PT-141 is a downstream, structurally distinct metabolite of that lineage. Its cyclic structure is reported to confer greater metabolic stability than linear α-MSH analogues. Because MC3R and MC4R are highly expressed in the hypothalamus and limbic system, PT-141 is frequently used as a reference agonist in central melanocortin research.
What does the research investigate?
Pre-clinical literature has used PT-141 to probe central melanocortin signalling, including MC3R/MC4R pharmacology, hypothalamic circuit function, autonomic modulation, and behavioural endpoints related to reward and arousal pathways in animal models. It is also cited in studies of blood-brain-barrier penetration by peptides. These are investigational findings from cell and animal research; they characterise receptor pharmacology and do not establish safety or efficacy for any human application. Always read the primary sources directly.
Purity and quality: what research buyers should check
- Purity of at least 99% by HPLC — confirm the figure against the batch-specific COA rather than a generic specification sheet.
- Identity confirmation by mass spectrometry — the measured mass should match the expected molecular weight of the peptide.
- Batch numbering — every vial should trace back to a documented production batch and its analytical records.
Vexar Lab supplies PT-141 as a pack of 10 vials, ≥99% HPLC-verified, batch-numbered, with mass-spec confirmation.
Handling and storage
PT-141 is supplied lyophilised. Standard laboratory practice for lyophilised peptides applies: store the sealed vials cold and protected from light, reconstitute only with an appropriate sterile solvent immediately before use, and aliquot to minimise repeated freeze-thaw cycles. Reconstituted peptide is generally less stable than the dry powder and should be refrigerated and used within a short working window. Follow your own institution’s handling protocols.
Wholesale supply
Vexar Lab supplies PT-141 to research buyers and resellers in packs of 10 vials, with a £300 minimum order, bulk pricing on volume, £45 flat worldwide shipping, and optional custom labelling for resellers.
Frequently asked questions
Is PT-141 approved for human use?
No. Vexar Lab supplies PT-141 strictly as a research material for in-vitro laboratory use. It is not sold for human consumption, and nothing here constitutes medical or dosing guidance.
What purity does Vexar Lab guarantee?
Each batch is verified at ≥99% by HPLC with identity confirmed by mass spectrometry, and every vial is batch-numbered against its COA.
How is it shipped and packaged?
It ships lyophilised in packs of 10 vials, with £45 flat worldwide shipping and batch documentation available on request.
This guide is provided for research-only purposes. PT-141 is supplied strictly for in-vitro laboratory research and is not approved for human consumption. No medical, therapeutic, or dosing advice is given or implied.
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