PT-141: A Melanocortin Peptide That Treats Sexual Dysfunction Through the Brain

PT-141 (bremelanotide), a synthetic alpha-MSH analog, induced erections in male animals and arousal in both sexes through central melanocortin MC3R/MC4R activation — the first centrally-acting peptide for sexual dysfunction.

Molinoff, P B et al.·Annals of the New York Academy of Sciences·2003·Moderate EvidenceAnimal StudyAnimal Study
RPEP-00849Animal StudyModerate Evidence2003RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

PT-141 (bremelanotide) induced sexual arousal in both male and female animals through central MC3R/MC4R activation, representing a mechanistically novel approach to sexual dysfunction treatment through brain desire pathways rather than peripheral blood flow.

Key Numbers

How They Did This

Preclinical studies in male and female animal models. PT-141 administered centrally and peripherally. Erectile and arousal responses measured. Receptor specificity confirmed with selective antagonists.

Why This Research Matters

Sexual dysfunction affects 40%+ of adults. Current drugs (Viagra) only address blood flow. PT-141 addresses desire/arousal centrally — helping patients where existing drugs fail.

The Bigger Picture

PT-141 (bremelanotide) was later approved by FDA as Vyleesi for hypoactive sexual desire disorder in women — the first melanocortin-based drug for sexual dysfunction, validating this research.

What This Study Doesn't Tell Us

Animal studies; human sexual dysfunction is more complex. Central peptide delivery may limit route options (intranasal or SC).

Questions This Raises

  • ?Does PT-141 work in human clinical trials?
  • ?Can a nasal spray or SC injection be practical for sexual dysfunction?
  • ?Does the melanocortin mechanism avoid the cardiovascular risks of PDE5 inhibitors?

Trust & Context

Key Stat:
Brain, not blood flow PT-141 works through the brain's desire centers (MC3R/MC4R), not peripheral blood flow like Viagra — effective when the problem is desire, not mechanics
Evidence Grade:
Moderate evidence from preclinical studies demonstrating clear central mechanism and both-sex efficacy.
Study Age:
Published in 2003. PT-141 (bremelanotide/Vyleesi) was FDA-approved in 2019 for hypoactive sexual desire disorder in premenopausal women.
Original Title:
PT-141: a melanocortin agonist for the treatment of sexual dysfunction.
Published In:
Annals of the New York Academy of Sciences, 994, 96-102 (2003)
Database ID:
RPEP-00849

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

What is PT-141/bremelanotide?

It's a synthetic peptide based on alpha-MSH that activates brain receptors controlling sexual desire. Unlike Viagra (which helps blood flow), PT-141 helps the brain generate desire and arousal — a fundamentally different approach.

Is this approved for use?

Yes — as Vyleesi (bremelanotide), it's FDA-approved for hypoactive sexual desire disorder (HSDD) in premenopausal women. It's given as a subcutaneous injection before anticipated sexual activity.

Read More on RethinkPeptides

Cite This Study

RPEP-00849·https://rethinkpeptides.com/research/RPEP-00849

APA

Molinoff, P B; Shadiack, A M; Earle, D; Diamond, L E; Quon, C Y. (2003). PT-141: a melanocortin agonist for the treatment of sexual dysfunction.. Annals of the New York Academy of Sciences, 994, 96-102.

MLA

Molinoff, P B, et al. "PT-141: a melanocortin agonist for the treatment of sexual dysfunction.." Annals of the New York Academy of Sciences, 2003.

RethinkPeptides

RethinkPeptides Research Database. "PT-141: a melanocortin agonist for the treatment of sexual d..." RPEP-00849. Retrieved from https://rethinkpeptides.com/research/molinoff-2003-pt141-a-melanocortin-agonist

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.