A melanocortin agonist developed from Melanotan II for MC4R, and studied for a central mechanism rather than a peripheral vascular one.
- Sequence
- Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
- Synonym
- bremelanotide
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- CAS number
- 189691-06-3
- Appearance
- white lyophilised powder
- Strength
- 10mg per vial
- Purity
- ≥99% by HPLC, identity confirmed by mass spectrometry
- Released against
- the Certificate of Analysis for its own batch
About PT-141
PT-141, also known as bremelanotide, is a cyclic heptapeptide and a metabolite of Melanotan II, differing from it by a free C-terminal carboxylic acid where Melanotan II carries an amide. It arose from the observation that Melanotan II produced central effects unrelated to pigmentation, and was developed to isolate that activity with a profile weighted towards MC4R.
The defining mechanistic point is that it acts centrally, on hypothalamic receptor populations. That places it in a different pharmacological category from the phosphodiesterase inhibitors it is sometimes grouped with in non-technical sources: those act on vascular smooth muscle, this acts on neurons.
What the research covers
MC4R is densely expressed in the hypothalamus and implicated in energy homeostasis and in the central component of sexual arousal. Most work on this compound concerns the latter, and it has the distinction, rare in this catalogue, of having been through controlled clinical trials as bremelanotide, so the evidence base is not confined to animal models.
Secondary strands cover appetite signalling through the same receptor and haemodynamic observations characteristic of melanocortin agonism. Because MC4R and MC1R activity are not fully separable even in a refined analogue, pigmentation-related observations still appear and are worth accounting for in a study design. Published work is indexed on PubMed.
Handling PT-141
Supplied lyophilised. As with any cyclic peptide, the analysis that matters is confirmation that the lactam bridge is present and correctly formed: a linear sequence of identical composition has nearly the same mass and a different receptor profile.
Reconstitute gently, store sealed at -20°C, and prepare working solutions fresh. Solvent options are under reconstitution supplies.
Other formats
PT-141 is also supplied as a metered 15ml PT-141 nasal spray, where no reconstitution step is needed.
Common questions about PT-141
Is PT-141 the same as bremelanotide?
Yes. Bremelanotide is the name under which it went through clinical trials.
How is PT-141 related to Melanotan II?
It is a metabolite of Melanotan II, differing at the C-terminus, developed to focus on MC4R activity rather than pigmentation.
Does PT-141 act on blood vessels?
No. It acts centrally on melanocortin receptors in the hypothalamus, unlike vascular agents such as phosphodiesterase inhibitors.
Why do pigmentation effects still appear?
MC4R and MC1R activity are not fully separable, so some MC1R-related observations persist even in this refined analogue.
How should PT-141 be stored?
Sealed vials at -20°C. Solutions are reconstituted gently and prepared fresh.
