Research guides

PT-141 (bremelanotide): what the research says

Approved in the US as Vyleesi, with two phase 3 trials and a published safety programme. The mechanism is neural at MC4R, not vascular like PDE5 inhibitors.

Available in the catalogue

Supplied as research material. Sizes and pricing are on the product page. Availability is not a statement about what a compound does.

PT-141 has something almost nothing else in this catalogue has: two completed phase 3 randomised trials, a regulatory approval, and a separately published analysis of safety across the whole development programme. It is a compound where the evidence question has a real answer.

What the molecule is

A cyclic seven-amino-acid peptide, and an active metabolite of Melanotan-2 that was developed as a compound in its own right. Approved in the United States as bremelanotide, marketed as Vyleesi.

A neural mechanism, not a vascular one

It acts mainly at MC4R in the central nervous system rather than on vascular tissue, which is what distinguishes it from the PDE5 inhibitors: the pathway it engages is neural rather than circulatory. It retains little of the pigmentation activity of its parent molecule, which was the point of developing it.

The trials

The RECONNECT programme comprised two randomised phase 3 trials in premenopausal women with hypoactive sexual desire disorder, together enrolling 1,267 participants, with efficacy and safety reported in 2019. A later paper examined the safety profile across the entire clinical development programme rather than a single trial, which is a more useful document than any individual study's adverse event table.

The approval that followed is specific: a defined indication, a defined population, an authorised formulation. The evidence is about that.

What studies reported

Each entry states what a study examined and the model it used. Nothing below describes an outcome for a person.

Everything below is drawn from published research, and each entry names the model the study used. Approval status varies by compound and by country, and nothing described here is supplied as a medicine or for use in a person.

  1. Kingsberg et al. (2019)Obstetrics & Gynecology · 134(5):899–908

    Reported efficacy and safety across 1,267 premenopausal women with hypoactive sexual desire disorder.

    human, two randomised phase 3 trials (RECONNECT) Source

Adverse and null findings reported

Harms, tolerability observations, and trials that did not meet their endpoint. A negative result is a finding and is listed here rather than omitted.

  1. Clayton et al. (2022)Journal of Women's Health · 31(2):171–82

    Examined the safety profile across the whole bremelanotide development programme rather than a single trial, characterising the pattern and frequency of treatment-emergent adverse events.

    human, pooled analysis across the clinical development programme Source

What the research does not establish

An absence cannot be cited, so these are stated plainly. They are the part of the picture that silence would otherwise hide.

  • The trial programme was conducted in premenopausal women with a diagnosed condition. No randomised trial has tested the compound in men, in postmenopausal women, or in people without the diagnosis, so the efficacy findings do not transfer.
  • The approved product has a regulatory label stating its adverse effect profile, contraindications and cautions in full. The safety analysis cited above is a published summary and not a substitute for that document.
  • Effects on blood pressure are part of the characterised profile of this compound and are managed through the label's cautions. A page like this one is not the place a reader should be getting that information.
  • Long-term use beyond the trial durations has not been characterised in published randomised work.
  • Material supplied here is a research reagent and is not the authorised medicine. None of the regulatory guarantees attached to Vyleesi apply to it.

Common questions

Is PT-141 approved?
Yes, in the United States as bremelanotide (Vyleesi), for hypoactive sexual desire disorder in premenopausal women. The approval is specific to that indication, population and formulation.
How does PT-141 differ from PDE5 inhibitors?
Mechanism. PT-141 acts mainly at MC4R in the central nervous system; the PDE5 inhibitors act on vascular tissue. The pathway is neural rather than circulatory.
How is PT-141 related to Melanotan-2?
It is an active metabolite of it, developed as a compound in its own right specifically to isolate the MC4R activity and leave the pigmentation behind. Unlike its parent it has phase 3 trials and an approval.
What did the RECONNECT trials find?
Two randomised phase 3 trials in 1,267 premenopausal women with hypoactive sexual desire disorder reported efficacy and safety results in 2019, and the approval followed.
Is the material supplied here the approved medicine?
No. It is a laboratory reagent for in-vitro research, supplied with a certificate of analysis, and not for human or veterinary use.

Compounds covered

The reference page for each compound this article discusses.

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