Bremelanotide - Frequently Asked Questions
Part of the full Bremelanotide guide - a synthetic cyclic heptapeptide; alpha-melanocyte-stimulating hormone reference compound, identity-verified with a COA on every vial.
Straight answers
Bremelanotide, answered
What class of peptide is PT-141 (bremelanotide)?
It is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a non-selective melanocortin receptor agonist, with characterized activity at the MC1R, MC3R, and MC4R subtypes.
What is the amino-acid sequence of PT-141?
The sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, an N-acetyl-Nle-capped heptapeptide cyclized by a lactam bridge between the Asp and Lys side chains.
What are the molecular formula and molecular weight?
The molecular formula is C50H68N14O10 and the average molecular weight is 1025.2 g/mol (free base), with a monoisotopic mass near 1024.5.
What is the CAS number for PT-141?
The free-base CAS Registry Number is 189691-06-3. The compound is also catalogued in PubChem under Compound ID (CID) 9941379.
Which receptors does PT-141 target in vitro?
It engages the melanocortin receptors MC1R, MC3R, and MC4R as a non-selective agonist, with reported binding favoring MC4R over MC3R and additional MC1R interaction.
What in-vitro functional readout is used to study PT-141?
Receptor occupancy couples to Gs and activates adenylate cyclase, raising intracellular cAMP. In MC4R-expressing HEK-293 cells, bremelanotide produces concentration-dependent cAMP accumulation in functional reporter assays, and it competes with radiolabeled NDP-alpha-MSH in competitive-binding assays.
Why is PT-141 more resistant to enzymatic degradation than linear melanocortins?
Its cyclic lactam bridge (Asp-Lys), the D-Phe substitution, and the N-acetyl-Nle cap constrain the backbone and block typical proteolytic recognition, conferring degradation resistance relative to flexible linear melanocortin peptides.
How is PT-141 reconstituted for laboratory in-vitro use?
The lyophilized powder is dissolved in bacteriostatic water to make a known-concentration stock, using the 1025.2 g/mol molecular weight to convert mass to molarity. Stock is refrigerated for short-term use and aliquoted frozen to avoid repeated freeze-thaw cycles. This is laboratory handling only, not a human dosing protocol.
Does the data provide a defined half-life for PT-141?
No specific half-life value is provided in the entry, so none is asserted. The data documents structure-driven enzymatic-degradation resistance and references pharmacokinetic study of intranasal PT-141, but storage longevity expectations rest on general peptide-class handling principles.
What is the foundational reference for PT-141's receptor characterization?
Molinoff, Shadiack, Earle, Diamond and Quon (2003), Annals of the New York Academy of Sciences, established PT-141 as a melanocortin agonist and is the source cited for its parent-hormone classification and primary in-vitro receptor targets.
What is the regulatory status of this material on this reference?
PT-141 is presented here strictly as a research-use-only reference compound. All framing is in-vitro, receptor-signaling, and laboratory-research oriented; the page provides no human dosing or administration guidance.
The fine print: products are sold for laboratory research use only and are not for human or animal consumption. Bodily introduction into humans or animals is strictly prohibited by law. Bremelanotide is not a drug and is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA.