Identity
| Names | PT-141; bremelanotide |
| Structure | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Description | A seven-residue peptide: N-acetylated norleucine followed by a six-residue ring, closed by an amide (lactam) bond between the aspartic acid and lysine side chains; contains one D amino acid (D-phenylalanine) |
| Molecular formula | C₅₀H₆₈N₁₄O₁₀ |
| Molecular weight | 1025.2 g/mol (monoisotopic mass 1024.5243) |
| CAS number | 189691-06-3 |
Reference data from PubChem (CID 9941379). Norleucine (Nle) is not one of the standard protein amino acids; the notation is explained in what is a peptide.
Specification and supply
| Strength | 10 mg per vial |
| Pack | Box of 10 vials |
| Codes | PT10 on the box; PT41 in our lists |
| Availability | In stock |
| Form | Lyophilised powder |
Documents and storage
Every batch ships with the manufacturer's certificate of analysis. Ask for the certificate of the current batch before you order. Safety data sheet: on request. Storage: as stated on the label. The tryptophan in the ring is sensitive to oxidation; see our storage and handling guide.
Calculated from the sequence
| Residues | 7 (six in the ring) |
| Approximate net charge at pH 7 | about 0 (one Arg; the Asp and Lys side chains form the ring; acetylated N-terminus, free C-terminal acid) |
| Character | Close to neutral |
| Oxidation-prone residues | One tryptophan |
These are estimates from the sequence, useful for planning laboratory work; the certificate of analysis reports the measured identity and purity of each batch.
Ordering for institutions
- Quotations within one working day, valid for 14 days, with lead time and delivery terms on one page.
- Invoices and documents in your institution's name; tell us if your purchase order needs to appear on them.
- Payment in full before dispatch, unless other terms are agreed in writing.
- Every shipment carries the batch number and expiry on the packing list and delivery note.
Who can buy it
Verified research buyers only, with a signed end-use declaration: laboratory research by qualified staff, no use in people or animals, no resale for those uses. We give no dosing or usage advice, and we don't supply sprays, pens or any form intended for use in people. What "research use only" means
Questions people ask
- Is PT-141 the same as bremelanotide?
Yes. Bremelanotide is the non-proprietary name for the peptide also called PT-141.
- What is the chemical structure of bremelanotide?
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH: an acetylated norleucine followed by a six-residue ring closed between the aspartic acid and lysine side chains.
- What is the CAS number of PT-141?
189691-06-3 (PubChem).
- Is your PT-141 a medicine?
No. It is a research-grade material for laboratory research only.