PT-141 Research Overview: Bremelanotide and the Melanocortin-4 Pathway
An overview of PT-141 (bremelanotide), the MC4R-selective melanocortin agonist studied in central nervous system signaling and sexual-behavior research models.
For in-vitro and laboratory research only. PT-141 is a research-grade peptide; nothing below should be interpreted as medical or clinical guidance.
PT-141 (bremelanotide) is a synthetic heptapeptide and selective agonist of the melanocortin-4 receptor (MC4R). It is structurally a metabolite-stabilized analog of Melanotan II, designed to retain the central melanocortin activity while reducing the MC1R-mediated pigmentation activity. Available as PT-141 10mg lyophilized.
The melanocortin receptor family in brief
- MC1R — melanocytes; pigmentation pathway.
- MC2R — adrenal cortex; cortisol synthesis (the ACTH receptor).
- MC3R — CNS; energy homeostasis.
- MC4R — CNS; appetite, autonomic regulation, sexual-response circuits.
- MC5R — exocrine glands; sebum-production research.
PT-141 is largely MC4R-driven, with reduced MC1R activity relative to Melanotan II — the structural rationale for its different research profile.
Mechanisms reported in published literature
- Central MC4R agonism. The most-cited mechanism is direct MC4R activation in hypothalamic neuronal populations.
- Pro-erectile behavior in rodent models. Published preclinical work consistently reports increased mounting behavior in rat models, with the effect blocked by MC4R antagonists.
- Autonomic effects. Some animal-model literature reports transient blood-pressure and flushing responses, consistent with autonomic engagement.
Common research-model applications
- Rodent sexual-behavior models for melanocortin pathway dissection
- MC4R receptor-binding and functional assays
- Comparative studies against Melanotan II to dissect MC1R vs MC4R contributions
Handling and storage
PT-141 ships lyophilized and follows standard peptide-handling protocol — see our peptide storage guide. Reconstitution is typically in bacteriostatic water.
Frequently confused with
- Melanotan II — the structural parent. See our Melanotan I vs Melanotan II comparison.
- Kisspeptin — Kisspeptin 5mg targets the reproductive HPG axis at a different node and is sometimes mistakenly grouped with PT-141 in the libido-research literature.
What to verify on the COA
- Sequence: heptapeptide bremelanotide sequence.
- Purity ≥98% by HPLC.
- Mass spec match.
See how to read a peptide COA.
Reminder: Content above is from preclinical research literature for laboratory and educational use. Products are not intended for human consumption.