FDA
1 application listed (Prescription)Drugs@FDA lists 1 application naming this active ingredient: NDA210557. Marketing status as listed: Prescription. Checked 2026-10-05.
Drugs@FDA via openFDAPT-141: chemistry, literature and regulatory status
Research-use information. This page summarises published literature and regulator records. It is not guidance for use, not medical advice, and not a statement that any material is suitable for use in people or animals.
What is PT-141?
PT-141, also called bremelanotide, is the cyclic heptapeptide Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, a melanocortin receptor agonist that differs from melanotan II at the C-terminus (free acid rather than amide). Published work covers receptor structure, medicinal chemistry and analytical characterisation. It is supplied here as a research material for laboratory use only.
What are the chemical facts for PT-141?
- Name
- PT-141
- Also written
- Bremelanotide
- Sequence
- Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
- Length
- 7 residues
- Molecular formula
C50H68N14O10(matches the formula computed from the sequence)- Average molecular weight
- 1025.2 g/mol
- CAS number
189691-06-3(confirmed in PubChem)- PubChem
- CID 9941379
Chemistry checked against PubChem on 2026-10-05. Where the formula can be computed from the listed sequence, it was, and the two routes agree.
How does the literature describe the mechanism of PT-141?
- Cryo-EM structures of full-length human MC4R were solved with alpha-MSH, afamelanotide, bremelanotide and a small-molecule ligand bound.[4]
- A review covers melanocortin receptor ligands beyond melanocyte-stimulating hormones and ACTH.[3]
- A medicinal-chemistry paper designs mid-size macrocycles for selective melanocortin-receptor targeting, with bremelanotide and setmelanotide as reference macrocycles.[2]
Receptor and pathway background: Melanocortin receptors.
What has published research on PT-141 looked at?
4 studies are cited for PT-141. Each is labelled by design below, and each entry says what the paper measured.
- 1 analytical chemistry
- 1 chemistry
- 1 review
- 1 structural biology
PubMed returns 114 records for the search terms published on the method page (56 of them with a review publication type, 17 with a clinical-trial publication type), checked 5 October 2026. ClinicalTrials.gov lists 10 registered studies whose intervention matches the name (10 interventional), checked 5 October 2026.
- A stability-indicating RP-HPLC method and LC-HRMS/MS characterisation of bremelanotide degradation products has been published.[1]
Studies are listed by what they measured. Papers whose titles state an amount or schedule, or describe a clinical outcome of an approved medicine, are not listed. This is a wording rule, not a quality filter; see the method page.
What is the regulatory status of PT-141?
EMA
No centrally authorised medicine listedNo centrally authorised procedure in the EMA medicines database (checked 5 October 2026) names bremelanotide as an active substance. National authorisations are not in this dataset.
EMA medicines dataMHRA
No product document foundNo SmPC, PIL or PAR document in MHRA Products matches the exact name "bremelanotide". Checked 2026-10-05; the control lookup (semaglutide) returned 271 documents.
MHRA ProductsWADA
Not namedThe WADA 2026 Prohibited List, in force 1 January 2026 does not name this substance. The list names substances by example, so this is not a statement that it is permitted in sport.
WADA Prohibited List 2026A regulator record is information about a database entry. It is not advice and not a statement that any use is lawful or unlawful in any country. How regulators approach research peptides.
Data dates: regulatory records 2026-10-05; WADA list 2026-10-05.
Which studies are cited for PT-141?
[1] Yuvaraaj VK, Sharma N. Comprehensive characterization of bremelanotide acetate and its degradants by LC-HRMS/MS and predicting epimerization through computational modelling. Anal Methods. 2026;18:6968-6982.
Stability-indicating RP-HPLC method and LC-HRMS/MS characterisation of bremelanotide degradation products.
[2] Merlino F, Jia L, Boccino I, Carotenuto A, Tammaro F, Santoro F, et al.. Goldilocks-Inspired Design of Mid-Size Macrocycles for Selective Targeting of Human Melanocortin Receptors. J Med Chem. 2026;69:18800-18812.
Design of mid-size macrocycles for selective melanocortin-receptor targeting, with bremelanotide and setmelanotide as reference macrocycles.
[3] Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules. 2022;12.
Review of melanocortin receptor ligands beyond melanocyte-stimulating hormones and ACTH.
[4] Zhang H, Chen LN, Yang D, Mao C, Shen Q, Feng W, et al.. Structural insights into ligand recognition and activation of the melanocortin-4 receptor. Cell Res. 2021;31:1163-1175.
Cryo-EM structures of full-length human MC4R bound to alpha-MSH, afamelanotide, bremelanotide and a small-molecule ligand.
Data dates: citations read from PubMed 2026-10-05.
Where else in the research library is PT-141 covered?
Who wrote this page and how is it checked?
Peptency editorial team, last reviewed 5 October 2026. Citations are read back from PubMed, chemistry is checked against PubChem, and regulator records are read from each regulator's own database on the dates shown. The method page lists every source, search term and rule. Corrections are welcome through the contact details on the About page.