PT-141 10mg
£15.99 per vial · Peptides · Research use only
About PT-141 10mg
PT-141 10mg is a synthetic cyclic peptide, also known as bremelanotide, supplied as lyophilised powder in a single vial for in-vitro laboratory research.
Product specifications
- Compound
- PT-141
- Declared content
- 10mg per vial
- Format
- Lyophilised powder
Batch documentation
The current published lot is IP-PT10-001. The batch record from Janoshik Analytical (CZ), dated 24 March 2026, lists reported purity of 99.809% (RP-HPLC) and measured content of 9.50 mg/vial.
View the certificate of analysis →
Intended use
For in-vitro laboratory research only. Not for human or veterinary use.
Technical notes and further reading
- CAS number
- 189691-06-3
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- Sequence
- cyclo Ac-Nle-[Asp-His-D-Phe-Arg-Trp-Lys]
Specification
| SKU | P41 |
|---|---|
| Compound | PT-141 |
| Price | £15.99 per vial |
| Format | 10mg per vial |
| Availability | In stock |
| CAS number | 189691-06-3 |
| Molecular formula | C50H68N14O10 |
| Molecular weight | 1025.2 g/mol |
| Sequence | cyclo Ac-Nle-[Asp-His-D-Phe-Arg-Trp-Lys] |
| Published batch / lot | IP-PT10-001 |
| Reported purity | 99.809% (RP-HPLC) |
| Measured content | 9.50 mg/vial |
| Identity status | LC-MS identity result not published |
| Tested by | Janoshik Analytical (CZ) |
| Report date | 2026-03-24 |
| Storage | Lyophilised: −20 °C, protect from light |
| Intended use | In-vitro laboratory research only |
What does the research on PT-141 investigate?
PT-141, also known as bremelanotide, is a cyclic heptapeptide and the ring is the defining feature. The chain is closed by a lactam bridge running from the side chain of an aspartate residue to the side chain of a lysine, which leaves the molecule with no free ends at all. That has consequences for both its stability and its analysis. With no termini to work from, the peptidases that would dismantle a linear peptide of the same length struggle to make a start, so a ring of seven residues resists breakdown better than a line of seven would. The ring has to be closed deliberately as a synthetic step, which means a preparation that assembled the sequence correctly but failed to cyclise contains a different, uncyclised molecule of the same residue composition. The chain also contains a tryptophan, the usual oxidation concern, and a D-configured phenylalanine. Nothing here describes a use, benefit, dose or effect in people.
Is PT-141 legal in the UK?
Bremelanotide is a licensed prescription medicine in the United States when presented for human use. The material listed here is not that product, is not licensed for any use, and is not supplied for human use. It is offered strictly as a research chemical for in-vitro laboratory work, and that framing is what makes the listing lawful rather than any property of the molecule.
Three pieces of legislation frame that distinction. The Human Medicines Regulations 2012 make it an offence to sell an unlicensed product for human use. The Psychoactive Substances Act 2016 prohibits supplying a psychoactive substance for human consumption, which is why a research-only basis is not a formality. The Misuse of Drugs Act 1971 would apply only if the compound were scheduled, and it is not. Each of these turns on the purpose of the supply, so the statements on this page are written plainly rather than tucked into small print.
In practice that means a supplier may lawfully sell to a researcher, research organisation or business buying for research, and the buyer confirms at checkout that they are 18 or over, buying in the course of research, and responsible for handling, storing and disposing of the material lawfully. Nothing here is legal advice for your own circumstances; if you need a position, take qualified advice.
The material listed here is not the licensed product, is not licensed for any use, and is not supplied for human use.
How are identity and quality assured?
Each released lot is tested and the result is published, rather than the material being described as high purity on the strength of a supplier's word. Purity is measured by reversed-phase HPLC at an independent laboratory. The laboratory used for every lot published so far is Janoshik Analytical, in the Czech Republic, and the result is stated alongside the measured content against label so the two can be read together.
The report carries the lot number printed on the vial, which is the part that matters. A certificate showing a result without a lot number cannot be tied to the vial in front of you, and a certificate for a different lot tells you nothing about yours. Matching the printed number on the label to the number on the report is a five second check and it is the whole point of publishing both.
Identity confirmation by mass spectrometry is a separate test and is ordered as an add-on, so the figures published here come from RP-HPLC purity testing unless a report says otherwise. Where no report is published for a listing yet, the documentation held for the lot being shipped can be requested before you order. We would rather send you what exists than let you assume a certificate is available when it is not.
Synthesis and supply
Peptide material is built by solid-phase synthesis, purified by preparative HPLC, then lyophilised. Lyophilisation freezes the solution and removes the solvent under vacuum, which is why the vial arrives holding a cake or powder rather than a liquid and why a solvent has to be added before the material can be worked with. Removing water also removes the main route by which a peptide degrades in storage, which is the reason the format is used.
Sequence length and modification are what make batches differ in difficulty. Every coupling step is an opportunity for a truncated or deleted by-product, and a heavily modified or long chain presents more of them, which is why the purity trace rather than the headline figure is what a certificate is read for. Vials are filled and labelled with the lot number, and the lot number is what the report and the verification lookup resolve against.
Cyclisation is a separate step after chain assembly, and an uncyclised linear precursor of the same sequence is the most likely closely related by-product, with the same residue composition but a different molecular weight.
External resources for researchers
These are the public reference sources we use when checking the identity of PT-141, and the ones worth going to before relying on anything stated on a product page, including this one.
- PubChem — Compound records, computed properties, depositor-supplied identity data.
- CAS Common Chemistry — CAS Registry lookups where a registry number is known.
- ChEBI — Curated chemical ontology entries with cross-references.
- Europe PMC — Primary literature search by compound name, sequence or registry number.
- Certificate hub — Reports published for the lots released so far.
Frequently asked questions
Why is high mass resolution important for this compound?
Its amidated structural counterpart sits about one mass unit away — replacing a C-terminal amide with a free carboxylic acid takes roughly 1024 to roughly 1025 — which is a narrow margin on a low-resolution instrument. Identity is therefore confirmed against retention time and the purity trace as well as the detected mass.
Does the ring change how the peptide behaves in protease-containing media?
A closed ring offers no chain end for an exopeptidase to start from, so ring-closed analogues generally persist longer in such media than their linear counterparts. That is a structural property of the molecule and not a claim about any system it is placed in.
Which receptor family does it belong to?
The melanocortin family — five G-protein-coupled receptors, MC1 through MC5. PT-141 is used in binding and signalling studies across those subtypes. Index Peptides lists it as a laboratory tool compound and says nothing about it beyond that.
Is PT-141 supplied for human or veterinary use?
No. Every product on this site is supplied strictly for in-vitro laboratory research. PT-141 is supplied as a lyophilised powder in a sealed vial and is not a medicine, supplement, food, cosmetic or veterinary product. It is not supplied for human or animal consumption, administration, or any in-vivo use, and no dose, route or human application is described or offered anywhere on this page. Buyers confirm they are 18 or over and purchasing in the course of research.
How is the purity figure measured, and what does it actually tell me?
Purity is measured by reversed-phase HPLC at an independent laboratory, and the result is published with the method conditions rather than as a bare percentage. The figure is the proportion of the UV-absorbing material in the chromatogram that elutes as the target peak. It describes the sample as analysed; it is not a statement about what the material is for. A high figure alongside a clean chromatogram is the useful combination, which is why the report is worth reading rather than the headline number alone.
What documentation comes with a batch?
Each released lot carries a number printed on the vial label and a report stating purity by RP-HPLC, measured content against label, and the testing laboratory. Reports published so far are listed on this page and collected on the certificate hub, and each carries a lot number that can be checked against the vial in front of you. Where a report is not yet published for a listing, ask before ordering and we will send the documentation that exists for the lot being shipped.
How should PT-141 be stored?
In the form supplied, as a lyophilised powder, the material is stable kept cold, dry and dark. For powder, that means a freezer at around minus 20 degrees Celsius, desiccated, with the vial sealed and shielded from light, which is how it should stay until you are ready to work with it. Bringing a vial to room temperature before opening avoids condensation on the contents. Once in solution the material is less stable than the powder and should be kept cold and used within a short working window. Choosing a solvent and a storage regime for your own work is your call, not ours.
Do I need bacteriostatic water to prepare it?
A lyophilised powder needs a solvent added before it can be worked with. Bacteriostatic water, which is water with 0.9% benzyl alcohol, is the common choice because the preservative extends the working life of the solution once the vial has been opened, and we supply it in 3ml and 10ml vials. It is not the only option: where a method cannot tolerate benzyl alcohol, use the solvent the method specifies. The choice affects the sample, so it belongs to the researcher.
How and when is an order shipped?
Orders are dispatched from the United Kingdom. An order placed before 4pm on a working day is collected the same day; weekends and bank holidays roll forward to the next working day. Delivery is tracked, and shipping is free on UK orders over 30 pounds, with tracked 48 hour service at 3.65 pounds below that. Tracking is sent when the parcel is collected, so the first scan is usually visible the same evening.
What does it mean that the peptide is cyclic?
That the chain has been joined into a ring, in this case by a bond between the aspartate and lysine side chains, so there is no N-terminal or C-terminal end. Proteins that break peptides down generally begin at an end, and a molecule without ends gives them little to grip. The ring also constrains the shape of the molecule, which affects how it presents to a receptor and how it retains on a chromatography column.
How can a certificate distinguish cyclised from uncyclised material?
By mass. The uncyclised precursor has the same residue composition but a measurably different mass, because the bond that closes the ring releases a molecule of water. A purity figure alone would not reveal the difference - both forms absorb ultraviolet light and both are peptides - so the mass result is doing the real work here. That is worth asking about specifically for any cyclic compound.
What is the tryptophan there for, analytically speaking?
It is the molecule's principal vulnerability. Tryptophan oxidises more readily than any other standard amino acid, and once oxidised the mass increases by sixteen daltons and the retention behaviour shifts. In a cyclic peptide this shows as a closely related neighbouring peak rather than an obvious impurity, and it is the change most likely to appear on a trace after a period of storage.
Is PT-141 the same as bremelanotide?
They are two names for the same molecule. Bremelanotide is a licensed prescription medicine in the United States when presented for human use, and the material listed here is not that product: it is not licensed for any use and is not supplied for human use. It is offered strictly as a research chemical for in-vitro laboratory work, which is the basis on which the listing is lawful.
Documentation & batch verification
The current released lot is IP-PT10-001, tested 2026-03-24 by Janoshik Analytical (CZ): RP-HPLC purity 99.809% (RP-HPLC), measured content 9.50 mg/vial, identity Purity confirmed (RP-HPLC). The full report for this lot is published and can be checked online — verify this batch. See the full record for lot IP-PT10-001 or all published certificates of analysis.
Published batch records show the laboratory, report date, purity and measured content where reported. Check the certificate for the exact lot: an HPLC purity result does not establish LC-MS identity, sterility or suitability for human or animal use. Review the published batch record before ordering.
Order PT-141 10mg online — UK dispatch · Request an invoice · Verify a batch
Research use only. Not for human or animal consumption.