PT-141
Bremelanotide · Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
Cyclic melanocortin receptor agonist, a metabolite-derived analogue of Melanotan II.
Total, ex VAT
£54.00
- Released at ≥ 98.0% (RP-HPLC, area %)
- Identity confirmed by ESI-MS against theoretical mass
- Batch certificate matched to the vial, verifiable online
- Same working day dispatch before 14:00, tracked
For laboratory research use only. Not for human or veterinary use, and not a medicine, food or cosmetic. Sold to qualified researchers and institutions who accept responsibility for safe handling and lawful use.
Compound data
What is in the vial
Indicative values for this line. The certificate issued with your batch is the authoritative record and reports the measured figures for the material you receive.
- CAS number
- 189691-06-3
- Molecular formula
- C50H68N14O10
- Average mass
- 1025.16 g/mol
- Residues
- 7
- Class
- Cyclic melanocortin receptor agonist
- Form as supplied
- Lyophilised powder
- Appearance
- White to off-white lyophilised powder
- Purity specification
- ≥ 98.0% (RP-HPLC, area %)
- Solubility
- Soluble in sterile or bacteriostatic water.
- Storage
- Lyophilised: −20 °C, desiccated and dark. Reconstituted: 2–8 °C.
Targets and pathways
- Melanocortin-4 receptor (MC4R)
- Melanocortin-3 receptor (MC3R)
Overview
About PT-141
PT-141 is a cyclic heptapeptide that arose as the deaminated metabolite of Melanotan II. It is an agonist at MC4R and MC3R with substantially reduced MC1R activity relative to its parent, which is why it separates central melanocortin signalling from pigmentation effects.
The lactam bridge that cyclises the molecule is central to both its receptor selectivity and its stability. Cyclic peptides of this type are robust in storage and resistant to exopeptidase attack, and this one is straightforward to handle compared with most compounds of similar length.
In short
- Cyclic heptapeptide with a lactam bridge
- MC4R and MC3R agonist with reduced MC1R activity relative to Melanotan II
- Cyclisation confers exopeptidase resistance and good storage stability
- Released at ≥ 98.0% area-percent by RP-HPLC
Where it is used
Research applications
Melanocortin receptor selectivity
The compound's shifted selectivity relative to its parent makes it a standard tool for separating MC4R from MC1R effects.
Central signalling
MC4R is a central regulator of energy balance and other behaviours, and the compound is used to probe those pathways.
Cyclic peptide chemistry
A worked example of lactam cyclisation as a route to both selectivity and stability.
Handling
Reconstitution and stability
Reconstitution
Reconstitute with sterile or bacteriostatic water added slowly against the inner wall of the vial. Allow the cake to dissolve without agitation, swirling gently if required. Do not vortex or shake.
Stability
Lyophilised at −20 °C, desiccated and protected from light, stable for at least 24 months. Reconstituted and held at 2–8 °C, use within 28 days. Avoid repeated freeze-thaw.
Notes
- Bring the vial to room temperature before opening so atmospheric moisture does not condense onto cold powder.
- Record the reconstitution date on the vial; concentration drift between runs is usually evaporation, not synthesis variance.
- Aliquot at first reconstitution where the working programme needs more than a few withdrawals.
Laboratory reference
Reconstitution calculator
Enter the fill weight on the vial and the diluent volume you intend to add. The calculator returns the resulting solution concentration and the volume that contains a given mass.
- Concentration
- 5.000 mg/mL · 5000 µg/mL
- Volume containing target mass
- 50.0 µL · 0.0500 mL
Figures are mass-to-volume arithmetic for laboratory preparation of PT-141 and take no account of net peptide content, which is stated on the batch certificate and should be applied to the fill weight before calculating. Nothing here constitutes dosing, administration or clinical guidance of any kind.
Published work
What the literature reports
Summaries of published findings, provided as research reference. These describe work done by others in preclinical and clinical settings; they are not claims about this material or outcomes for any reader.
Analogue characterisation
Description of the compound's receptor binding profile relative to Melanotan II and the native melanocortins.
Molinoff et al., Annals of the New York Academy of Sciences, 2003
Melanocortin receptor pharmacology
Comprehensive treatment of the receptor family and the structural basis of subtype selectivity.
Reviewed in Yang, Peptides
Questions
PT-141 — asked and answered
Something not covered here? Ask us directly — technical questions reach someone who runs the assays.
- How does it differ from Melanotan II?
- PT-141 is the deaminated metabolite. It retains MC4R and MC3R agonism but has markedly reduced MC1R activity, which is the pigmentation receptor. That shift in selectivity is the point of the compound.
- Is it stable?
- Yes, notably so. The lactam bridge confers exopeptidase resistance and cyclic peptides of this class store well. 28 days in solution at 2–8 °C.
- Is bremelanotide the same?
- Yes. Bremelanotide is the international nonproprietary name for PT-141.
Important
PT-141 is supplied strictly for laboratory research and analytical use. It is not a medicine, food, cosmetic or veterinary product; it is not for human or animal consumption; and it is not intended to diagnose, treat, cure or prevent any condition. It is not manufactured, tested or released to any standard that would support administration to humans or animals. Information on this page is compiled for research reference and is not medical advice. No dosing, administration or therapeutic guidance is given or implied. By ordering you confirm you are a qualified researcher or institution and accept responsibility for safe handling and lawful use.