Bremelanotide: the basics
What is it?
A prescription peptide that acts on melanocortin receptors, which are involved in several brain and body signals.
Prescribing information ↗What do people claim it helps with?
Improving distressing low sexual desire is an approved use for a specific group. Claims of a general libido boost or erectile-dysfunction treatment go beyond its approval.
What has research actually shown?
Controlled trials found improvements in desire and related distress in selected premenopausal women with acquired, generalized hypoactive sexual desire disorder.
Prescribing information ↗Has this been demonstrated in people?
Demonstrated in people, including controlled clinical trials for the uses described here. Evidence for one diagnosis does not establish benefit for every other claim.
Prescribing information ↗What side effects, risks and unknowns should I understand?
Nausea, flushing and headache are common. It can temporarily raise blood pressure and cause skin darkening. It is contraindicated with uncontrolled hypertension or known cardiovascular disease.
Prescribing information ↗Is it an approved medicine?
Yes. Vyleesi is FDA-approved for acquired, generalized hypoactive sexual desire disorder in premenopausal women meeting the label’s criteria; not for men or sexual-performance enhancement.
Prescribing information ↗Approval here means U.S. FDA approval and applies to a particular product, formulation and use. This is a starting overview, not a complete side-effect list. Sources checked 10 October 2026; independent scientific review pending.
How is it used or studied?
Prescription injection, after assessment of the cause of low desire and cardiovascular suitability.
Different routes and formulations can have different effects. A study of one product does not validate every product with the same peptide name.
A common misunderstanding
Sexual desire and erectile function are different outcomes.
What should I ask a clinician?
- What diagnosis or goal are we trying to address, and what established options are available?
- Was the expected benefit shown in people like me, using this exact product?
- How could my medicines, health conditions or pregnancy plans affect the risks?
- What monitoring is needed, and what would tell us the treatment is helping or should be stopped?
What do the research words mean?
- Peptide
- A short chain of amino acids, the building blocks of proteins.
- Preclinical
- Research in cells, tissues or animals before dependable treatment evidence in people.
- Controlled trial
- A study comparing a treatment with another treatment or a placebo to help separate its effects from other explanations.
- Biomarker
- A measurement, such as a hormone level. A change does not necessarily mean someone feels better or lives longer.
Bremelanotide Evidence & Clinical Profile
Established Clinical Trials
Bremelanotide has been investigated in clinical contexts. Patient outcomes must be evaluated against study size, design, and control cohorts.
Laboratory & In Vivo Assays
Cellular and animal disease models examine receptor binding affinities and signaling cascades, which require human confirmation.
What is Bremelanotide?
Bremelanotide Acetate (Vyleesi / PT-141) is An FDA-approved cyclic heptapeptide melanocortin receptor agonist (acting at receptors including MC3R and MC4R, expressed mainly in the central nervous system). Clinically indicated for hypoactive sexual desire disorder (HSDD) in premenopausal women. Aliases include: Vyleesi, PT-141, Cyclic Melanocortin Agonist.
- Sequence (one-letter)
- Ac-Nle-c[DH-D-Phe-RWK]
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- CAS Number
- 189691-06-3
- UNII Code
- 6Y24O4F92S
- PubChem CID
- 9941379
Identifiers are for the free base. The approved medicine contains bremelanotide acetate (UNII PV2WI7495P).
Identifiers checked against PubChem and FDA's Global Substance Registration System on 13 October 2026. FDA substance record ↗ · PubChem record ↗ See all names and codes in the peptide name index.
Clinical Trials & Human Cohorts
Human research can examine tolerability, symptoms or patient outcomes. The design and comparator determine what each result can establish.
Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials [1]
What was reported
Statistically significant increases in sexual desire (FSFI-desire) and reductions in desire-related distress (FSDS-DAO item 13) compared to placebo in both studies.
What limits the conclusion
Nausea, flushing and headache were more common than with placebo (10% or more in both studies); participants were mostly white and from U.S. sites.
Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141 in healthy male subjects and in patients with an inadequate response to Viagra [2]
What was reported
Produced statistically significant RigiScan-measured erectile responses in healthy men and in ED patients; reported as safe and well tolerated.
What limits the conclusion
Early-phase study; sample sizes are not given in the abstract and erections were measured in a laboratory setting.
How the compound may work
Mechanisms describe how Bremelanotide may affect biological processes. Laboratory findings and patient outcomes answer different questions.
Central Melanocortin Receptor Activation
An alpha-MSH analogue that acts as an agonist at melanocortin receptors including MC3R and MC4R; in rats, systemic administration activated hypothalamic neurons (increased c-Fos). [3]
Areas Being Studied
These research topics reflect active areas of scientific exploration, distinct from unverified commercial marketing claims.
Hypoactive Sexual Desire Disorder (HSDD)
Improved sexual desire and related distress versus placebo in premenopausal women. [1]
Male Erectile Dysfunction
Produced erectile responses in healthy men and in men with ED who responded inadequately to Viagra; not approved for this use. [2]
Compare the study designs.
| Study | Design / sample | Outcome type | Key limitation |
|---|---|---|---|
| RECONNECT Phase 3 Trials · 2019 [1] | Two identical multicenter randomized double-blind placebo-controlled Phase 3 RCTs n = 1247 |
Clinical endpoint evaluation | Nausea, flushing and headache were more common than with placebo (10% or more in both studies); participants were mostly white and from U.S. sites. |
| Early Male Clinical Study · 2004 [2] | Dose-ranging study in healthy men plus placebo-controlled crossover in ED patients n = not stated in abstract |
Clinical endpoint evaluation | Early-phase study; sample sizes are not given in the abstract and erections were measured in a laboratory setting. |
Regulatory Status & Clinical Safety
Regulatory Classification
FDA approved (NDA 210557) as Vyleesi subcutaneous autoinjector.
Safety Realities & Impurities
Safety depends on the molecule, formulation, route and evidence. A laboratory purity measurement alone cannot establish safety for human use.
Clinical Trials Registry Records
Official registry records from ClinicalTrials.gov. Study registration does not imply government endorsement or guaranteed efficacy.
2. Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder [1]
- Planned enrollment
- 714 (patients)
- Posted results
- Available
- Sponsor
- Palatin Technologies
- Last updated
- 2021
WADA & Anti-Doping Regulations
WADA Anti-Doping Status
Bremelanotide is not prohibited under current World Anti-Doping Agency (WADA) regulations. However, athletes must ensure unregulated preparations or unverified vendor products do not violate Section S0 (Non-approved substances). Last verified: October 2026.
Research Timeline
What Researchers Still Don't Know
Long-term safety profiles
Multi-year observational data in broader heterogeneous cohorts remains uncharacterized.
Optimal dose-response thresholds
Comparative trials optimizing minimal effective exposure versus adverse event rates.
Formulation bioavailability
Differences between oral, subcutaneous, and modified peptide delivery vehicles.
References
Primary sources verified against PubMed / NLM and regulatory databases.
- Phase 3 RCT
- Early Clinical Study
-
Receptor Biology
PT-141: a melanocortin agonist for the treatment of sexual dysfunction ↗ (external website)
-
Regulatory
FDA Drug Approval Package: Vyleesi (Bremelanotide) ↗ (external website)