PT-141 (Bremelanotide): Research Overview and Identifiers
Quick Answer
PT-141, also called bremelanotide, is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors, chiefly MC4R and MC3R. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (C50H68N14O10, about 1025.2 g/mol, CAS 189691-06-3). It is closely related to Melanotan II and is studied in melanocortin-receptor binding and central melanocortin signalling research.
Key Takeaways
- PT-141 and bremelanotide are the same compound.
- A cyclic seven-residue peptide built on the melanocortin core sequence His-D-Phe-Arg-Trp.
- Differs from Melanotan II only at the C-terminus: a free acid (-OH) instead of an amide (-NH2).
- Studied as an agonist at MC4R and MC3R in receptor and signalling assays.
- Each Cellugenix lot is independently tested; the certificate is in the COA library.
Identifiers
| Field | Value |
|---|---|
| Other names | Bremelanotide, PT 141, PT141 |
| Sequence | Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH |
| Molecular formula | C50H68N14O10 |
| Molecular weight | 1025.2 g/mol |
| CAS number | 189691-06-3 |
| Structure | Cyclic heptapeptide (lactam bridge between Asp and Lys) |
| Form | Lyophilized solid, sealed vial |
Origin and Structure
PT-141 was developed from Melanotan II, a cyclic analogue of alpha-melanocyte-stimulating hormone (alpha-MSH). Both share the ring formed between aspartic acid and lysine and the His-D-Phe-Arg-Trp core that binds melanocortin receptors. PT-141 carries a free carboxylic acid at the C-terminus where Melanotan II has an amide. For a side-by-side comparison, see PT-141 vs Melanotan II.
Research Areas
- MC4R and MC3R receptor binding and selectivity
- Central melanocortin signalling pathways
- Structure-activity studies of cyclic alpha-MSH analogues
Related compounds: Melanotan II and Kisspeptin-10.
Storage of the Sealed Vial
PT-141 ships as a lyophilized (freeze-dried) solid in a sealed vial labelled with its lot number. Store sealed vials as stated on the label, protected from light and moisture; see our storage and handling guide.
Analytical Verification and Documentation
The current PT-141 10 mg lot was tested by Testides, an independent laboratory, at Purity by HPLC (report LK-PT1-10-021126, tested February 23, 2026). The certificate is published with its report number so it can be checked against the lab’s record: PT-141 10 mg certificate. New to certificates? Read how to read a COA.
Frequently Asked Questions
What is PT-141?
PT-141 is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors, mainly MC4R and MC3R. It is studied in melanocortin-receptor and central signalling research.
Is PT-141 the same as bremelanotide?
Yes. Bremelanotide is the non-proprietary name of the compound known as PT-141.
What is the difference between PT-141 and Melanotan II?
They share the same cyclic core. PT-141 has a free acid (-OH) at the C-terminus, while Melanotan II has an amide (-NH2), which changes the molecular weight slightly (1025.2 vs 1024.2 g/mol).
What is the CAS number of PT-141?
The CAS number of PT-141 (bremelanotide) is 189691-06-3.
What is the molecular weight of PT-141?
About 1025.2 g/mol, for the formula C50H68N14O10.
How pure is Cellugenix PT-141?
The current 10 mg lot tested at Purity by HPLC by Testides (report LK-PT1-10-021126). The certificate is in the COA library.
Sold for in-vitro laboratory research only. Not for human or animal use and not for diagnostic or therapeutic procedures. Nothing here describes or suggests use in people.
For Research Use Only. Not for use in diagnostic or therapeutic procedures.
