Peptigrade

Sexual Health

PT-141

Bremelanotide·Also known as: Vyleesi, PT 141

FDARegulatory status

Approved (2019, for premenopausal HSDD in women, brand name Vyleesi)

WADARegulatory status

Not specifically prohibited for non-athletes; melanocortin agonists are reviewed periodically.

Regulatory note ·FDA-approved for premenopausal hypoactive sexual desire disorder (HSDD) in women. Used off-label in men for erectile dysfunction. Marketed by Palatin Technologies / AMAG.

§ The quick take

TL;DR · Editor’s summary

PT-141 (bremelanotide) is one of the few peptide drugs explicitly approved by the FDA — for premenopausal HSDD in women, branded as Vyleesi. The trials show real but modest effect sizes.

Side effects (nausea, flushing, transient blood pressure increase) are common. Use in men for ED is off-label and supported by earlier-phase data only.

The honest read: B-grade for the on-label indication, C-grade for off-label sexual function uses.

§ Grade matrix

The grade
per outcome.

One peptide can earn very different grades for different uses. Here is every outcome we’ve graded for PT-141, sorted by strength of evidence.

B

Hypoactive sexual desire disorder (HSDD, women)

Promising

RECONNECT Phase 3 trials showed statistically significant improvement in desire and reduction in distress vs placebo, though absolute effect size is modest.

28 studiesUpdated Mar 12, 2026
C

Erectile dysfunction (men)

Mixed

Phase 2 evidence in men with PDE5-inhibitor non-response. Development for ED was halted before Phase 3.

14 studiesUpdated Feb 18, 2026
C

Female sexual arousal (FSAD)

Mixed

Earlier-phase studies positive, but PT-141 was advanced for HSDD rather than FSAD.

9 studiesUpdated Feb 02, 2026

§ Why this grade

Sub-scores for this outcome.

HSDD (women)

Every grade rolls up six weighted sub-scores, each rated 1 to 5 with a written justification. Here is how the top-outcome grade was constructed.

Mechanism understood

4 / 5

MC4R agonism in CNS sexual circuits is well-characterized.

Human studies (count + quality)

4 / 5

Two Phase 3 RCTs (RECONNECT-1 and RECONNECT-2) plus open-label extensions.

Effect vs placebo

3 / 5

Statistically significant but modest absolute effect size.

Long-term safety data

3 / 5

Approved use is on-demand; chronic exposure data limited.

Side effect profile

2 / 5

Nausea (40%+), flushing, BP elevation. Discontinuation rates non-trivial.

Regulatory status

5 / 5

FDA-approved 2019. EMA review pending.

§ What the science says

How PT-141
works.

The scientific explanation of the molecule and its proposed mechanism, with a plain-English translation — written at an 8th-grade reading level — in the teal callouts below each section. Every claim is linked to a primary source below.

What it is

PT-141 (bremelanotide) is a 7-amino-acid synthetic melanocortin receptor agonist developed from the larger compound Melanotan II. It was developed by Palatin Technologies and approved by the FDA in 2019 as Vyleesi for the treatment of hypoactive sexual desire disorder in premenopausal women. It works centrally — at the brain — rather than peripherally on vasculature like PDE5 inhibitors.

In plain English

PT-141 (bremelanotide) is a lab-made 7-amino-acid peptide. It was developed out of a bigger molecule called Melanotan II. Palatin Technologies brought it through the FDA, and it was approved in 2019 as Vyleesi for women with low sexual desire. Unlike Viagra-type drugs that work on blood flow, PT-141 works in the brain.

How it works

  1. 01

    PT-141 activates melanocortin receptors in the central nervous system, particularly MC4R, which is involved in sexual function pathways in the hypothalamus.

    In plain English

    PT-141 turns on melanocortin receivers in the brain — especially one called MC4R — that are part of the brain's sexual-desire circuit (located in the hypothalamus).

  2. 02

    Unlike PDE5 inhibitors (sildenafil, tadalafil), it acts on desire and arousal at the brain level rather than improving genital blood flow.

    In plain English

    Unlike Viagra or Cialis, which work by boosting blood flow to the genitals, PT-141 works on desire and arousal in the brain itself.

  3. 03

    The exact downstream circuitry is not fully mapped, but melanocortin signaling intersects with dopaminergic reward pathways implicated in sexual motivation.

    In plain English

    The full brain circuit isn't completely mapped out yet, but the melanocortin signal overlaps with dopamine (the brain's reward chemical), which is known to play a role in sexual motivation.

  4. 04

    Subcutaneous administration produces effects within ~45 minutes that persist for several hours.

    In plain English

    Injected under the skin, it starts working in about 45 minutes and lasts several hours.

§ Investigated uses

What it’s
been studied for.

Investigated does not mean proven. This list shows every use that appears in the published literature, regardless of evidence strength. See the grade matrix above for which ones have actually held up.

  • Hypoactive sexual desire disorder (premenopausal women)

    FDA-approved (Vyleesi) — Grade B

  • Erectile dysfunction in PDE5-inhibitor non-responders

    Phase 2 positive, no Phase 3 — Grade C

  • Female sexual arousal disorder

    Earlier-phase evidence — Grade C

  • Melanocortin-system obesity (research)

    Setmelanotide is the related approved drug for genetic obesity

§ The honest gaps

What we don’t
know yet.

Every peptide page on this site is required to include this section. Absence of evidence is information. If we don’t flag the gaps, we’re lying by omission.

  • !

    Long-term safety beyond approved on-demand use is not characterized.

  • !

    Whether the modest effect size (about 0.5 point improvement on FSFI desire scale vs placebo) translates to meaningful real-world satisfaction is debated.

  • !

    Whether men can safely use it off-label given cardiovascular concerns (transient BP increase) is not clearly established.

  • !

    Comparative effectiveness vs other interventions for HSDD (psychotherapy, hormonal therapy, flibanserin) is poorly studied.

§ On YouTube

What experts and
influencers say.

We index YouTube content discussing PT-141and tag every speaker by credential and trust level. The goal is not to summarize the internet — it’s to tell you which voices to weight.

  • Vyleesi (Bremelanotide) Explained — A Clinician's View

    Mama Doctor Jones·MD, OB/GYN

    Honest discussion of the modest effect size and side effects, particularly nausea.

    Verified credentials

§ Citations

Every claim,
linked to source.

All 3 sources informing this page, with DOI or PubMed identifiers. Click through to the primary literature.

  1. [01]

    Bremelanotide for hypoactive sexual desire disorder: pooled analysis of RECONNECT-1 and RECONNECT-2

    Kingsberg SA, Clayton AH, Portman D, et al. · Obstet Gynecol · 2019

    RCTPMID 31441211
  2. [02]

    Bremelanotide for erectile dysfunction: Phase 2 results

    Diamond LE, Earle DC, Heiman JR, et al. · Int J Impot Res · 2006

    RCTPMID 16877794
  3. [03]

    Bremelanotide for female sexual dysfunction: a review

    Mayer ME, Burchill MV · Pharmacotherapy · 2020

    Systematic reviewPMID 32008311

§ Adjacent peptides

Worth reading
alongside this.

Where to research further

Looking for PT-141
for laboratory research?

Peptigrade does not sell peptides. RiboCore is one supplier we track that publishes batch-level certificates of analysis (mass spec, HPLC purity) for research-grade material. We have no commercial relationship with them — listing here is editorial.

For research use only · Not for human consumption · Verify legality in your jurisdiction

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