What is PT-141 approved for?

PT-141 (bremelanotide/Vyleesi) is FDA-approved in the US for treating hypoactive sexual desire disorder (HSDD) in premenopausal women. It is not approved in the UK or EU.

Does PT-141 work for men?

Research has shown PT-141 can produce erections in men with erectile dysfunction. However, it is not approved for this use, and development focused on female HSDD. Male use would be off-label.

How is PT-141 different from Viagra?

PT-141 works on central brain pathways affecting desire and arousal, while Viagra (sildenafil) works on peripheral blood flow. PT-141 addresses psychological/desire aspects; Viagra addresses physical blood flow.

Is PT-141 available in the UK?

PT-141/Vyleesi is not licensed in the UK. It may be available through specialist physicians or as a research compound, but is not available on NHS prescription.

Fact-checked by the Peptide Authority Editorial Board · Last reviewed: 1 February 2026

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Sexual Health & Tanning•Updated 2026-02-01•6 min read

What Is PT-141? Benefits, Research & Safety

An FDA-approved melanocortin receptor agonist for treatment of hypoactive sexual desire disorder in premenopausal women.

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Also known as:

Bremelanotide

Vyleesi

BModerate human evidenceUK: Unlicensed (UK)WADA: Sport status unclear

UK summary: Bremelanotide is FDA-approved as Vyleesi for HSDD in premenopausal women in the US, but is not licensed in the UK. Cardiovascular effects (blood-pressure rise) are documented. Sport status uncertain; confirm before competition.

Quick Facts

Overview

PT-141, now known by its approved name bremelanotide and sold under the brand name Vyleesi, is a melanocortin receptor agonist derived from Melanotan II research. Unlike its parent compound, PT-141 was specifically developed to target sexual function without significant tanning effects. Bremelanotide represents a significant advancement in sexual medicine as the first FDA-approved treatment specifically for hypoactive sexual desire disorder (HSDD) in premenopausal women. Its approval in 2019 provided a new treatment option for a condition affecting a substantial proportion of women. The peptide works through a fundamentally different mechanism than existing erectile dysfunction treatments. While PDE5 inhibitors like sildenafil act on peripheral blood flow, PT-141 works centrally through melanocortin receptors in the brain, affecting the neural pathways involved in sexual arousal and desire. PT-141 has also been investigated for male erectile dysfunction, though it is not currently approved for this indication. Research continues into potential applications and optimisation of delivery methods. As an approved medication (Vyleesi), bremelanotide is available by prescription in the United States. It is not currently approved in the UK or EU, where it remains a research compound or may be available through specialist channels.

Evidence standards summary

PT-141 — evidence and risk at a glance

Twenty standard modules scored against the Peptide Authority evidence grading methodology. Missing modules indicate the field has not yet been characterised editorially — treat absences as uncertainty rather than reassurance.

01Evidence snapshot

BModerate human evidenceOverall grade against our evidence grading methodology.

Bremelanotide is FDA-approved as Vyleesi for HSDD in premenopausal women in the US, but is not licensed in the UK. Cardiovascular effects (blood-pressure rise) are documented. Sport status uncertain; confirm before competition.

02Human evidence grade

AStrong human evidenceStrength of evidence from published human trials.

03Preclinical evidence grade

AStrong human evidenceAnimal-model and in-vitro evidence quality.

04Regulatory status

UK: Not approved. Available only through specialist channels or as research compound.
EU: Not approved by EMA. Not available as licensed medicine.
Notes: PT-141 (bremelanotide/Vyleesi) is FDA-approved in the United States for HSDD in premenopausal women since 2019. It is not approved in UK or EU. WADA prohibits its use in competitive sport.

05Approved medical uses

Hypoactive sexual desire disorder (HSDD) in premenopausal women (FDA-approved as Vyleesi in the US; NOT MHRA-licensed in the UK).

06Unapproved / promotional claims

Safer than Viagra for erectile dysfunction.
Works for everyone with no responder variability.
Available routinely on UK prescription.
Safe to combine with PDE5 inhibitors or recreational stimulants.

07Common internet claims

Marketed online as a unisex 'sexual arousal' peptide.
Sold by grey-market clinics on the FDA approval for the US-only Vyleesi indication.
Promoted as a Viagra alternative for men with normal vascular function.

08Claim vs evidence

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“FDA-approved for sexual dysfunction”	A	Yes	Low	Vyleesi is FDA-approved for HSDD in premenopausal women in the US; this is not the same as UK MHRA approval.
“Available in the UK on prescription”	E	No	High	PT-141 / bremelanotide is not a UK-licensed medicine; some specialist routes may exist but not via standard NHS prescription.
“Safer than Viagra”	E	No	High	Comparative-safety claims need comparative trials. PDE5 inhibitors have substantial UK clinical use; bremelanotide has its own cardiovascular profile.
“Works for everyone”	C	Limited	Moderate	Trial response rates are moderate; significant non-responder fraction.

09Safety uncertainty score

Moderate

Safety profile partly characterised; some signals from observational or preclinical data.

10Known adverse signals

Transient blood-pressure rise (documented; major reason for FDA dose-frequency limits).
Nausea, flushing, headache (common in trials).
Skin hyperpigmentation with repeated use.
Contraindicated in uncontrolled hypertension or cardiovascular disease.

11Drug-interaction uncertainty

Moderate

Some interaction data published; check with a prescriber for your specific medicines.

12Anti-doping status

WADA: Sport status unclearWADA strict-liability framing applies.

13UK legal position

UK: Unlicensed (UK)

Not approved. Available only through specialist channels or as research compound.

Read the full UK legal guide → Are peptides legal in the UK?

14EU legal position

Not approved by EMA. Not available as licensed medicine.

15What this page cannot tell you

Whether a UK-purchased vial actually contains bremelanotide at the labelled concentration.
Whether off-label male ED use carries the same safety profile as licensed female-HSDD use.
How it interacts with PDE5 inhibitors (sildenafil, tadalafil) — not formally studied.
Whether you have undiagnosed cardiovascular risk that would make the BP rise dangerous.

16Last reviewed

Last reviewed: 1 February 2026

Next review due: 1 February 2027

Spotted an error or something out of date? Send a correction.

17Citation quality score

BModerate human evidenceQuality of the sources we cite, graded against the evidence grading methodology.

18Research gaps

Male ED Phase 3 trials not published despite extensive promotion.
Long-term cardiovascular safety beyond ~12 months unstudied.
Combination safety with PDE5 inhibitors uncharacterised.
No UK regulatory submission pathway active.

19Safer alternatives / established care pathways

GP review for ED — licensed PDE5 inhibitors (sildenafil, tadalafil) are first-line, available NHS in selected groups, widely available privately.
GP / psychosexual therapy referral for HSDD in women — talking therapy is NICE first-line.
Cardiovascular risk assessment before any pharmacological sexual-health intervention.

20Doctor discussion prompts

Questions to ask a qualified clinician

These are starter questions you can adapt for a GP, specialist, pharmacist, or anti-doping advisor. The aim is to help you have a better-informed conversation — not to replace one.

Is PT-141 / bremelanotide licensed in the UK?
What licensed UK alternatives exist for the sexual-health concern I'm asking about?
Do I have cardiovascular risk factors that would make bremelanotide unsuitable?
If accessed privately, what is the supply-chain provenance?

Discovery & History

PT-141 emerged from research into Melanotan II at the University of Arizona. During clinical trials of Melanotan II for tanning, researchers observed significant effects on sexual function, including spontaneous erections in men and increased arousal in women. Recognizing the therapeutic potential, Palatin Technologies acquired rights to develop a derivative specifically targeting sexual dysfunction. PT-141 was designed as a metabolite of Melanotan II with reduced pigmentation effects but retained activity at melanocortin receptors involved in sexual function. Clinical development proceeded through multiple trials for both male erectile dysfunction and female sexual dysfunction. Initial development for ED was complicated by blood pressure effects observed with intravenous and intranasal administration. The focus shifted to female hypoactive sexual desire disorder, where subcutaneous administration showed efficacy with an acceptable safety profile. Phase III trials (RECONNECT studies) demonstrated statistically significant improvements in desire and reduction in distress. In 2019, the FDA approved bremelanotide (Vyleesi) for HSDD in premenopausal women, making it the first centrally-acting treatment for this condition. The approval came with a boxed warning regarding nausea and blood pressure effects. Research continues into potential applications including male sexual dysfunction, though no additional approvals have been granted.

Mechanism of Action

PT-141 works through activation of melanocortin receptors, particularly MC4R, in the central nervous system: **Central Melanocortin Pathway Activation** PT-141 activates MC4R and MC3R in hypothalamic and limbic brain regions involved in sexual behavior: - Direct effects on arousal centres in the hypothalamus - Modulation of dopaminergic pathways involved in desire and motivation - Influences on oxytocinergic systems linked to bonding and arousal - Integration of desire, arousal, and pleasure circuits **Mechanism Distinct from PDE5 Inhibitors** Unlike sildenafil and similar drugs: - Works on central desire and arousal rather than peripheral blood flow - Effective in both men and women through central pathways - Addresses desire/motivation aspects rather than purely physical function - Does not require sexual stimulation to be present initially **Receptor Selectivity** PT-141 has modifications compared to Melanotan II that reduce: - MC1R activity (less pigmentation effect) - Duration of action - Systemic exposure However, it retains: - MC4R agonism (sexual function) - Some MC3R activity - Sufficient potency for therapeutic effect

Researched Benefits

Based on preclinical and clinical research findings:

1
Increased sexual desire in women with HSDD (approved indication)
2
Reduced distress associated with low sexual desire
3
Enhanced sexual arousal independent of peripheral mechanisms
4
Potential efficacy in male erectile dysfunction (research)
5
Works through novel central mechanism
6
On-demand use (not daily medication)

Claim vs Evidence

How popular claims about PT-141 stack up against the current research, graded using our public evidence grading methodology.

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“FDA-approved for sexual dysfunction”	A	Yes	Low	Vyleesi is FDA-approved for HSDD in premenopausal women in the US; this is not the same as UK MHRA approval.
“Available in the UK on prescription”	E	No	High	PT-141 / bremelanotide is not a UK-licensed medicine; some specialist routes may exist but not via standard NHS prescription.
“Safer than Viagra”	E	No	High	Comparative-safety claims need comparative trials. PDE5 inhibitors have substantial UK clinical use; bremelanotide has its own cardiovascular profile.
“Works for everyone”	C	Limited	Moderate	Trial response rates are moderate; significant non-responder fraction.

Theoretical Dosing & Protocols

⚠️ Educational Only: The following information is derived from research literature and is not a prescription or recommendation. No standardised human dosing exists. Always consult a qualified healthcare professional.

Theoretical Dosage	1.75 mg subcutaneous injection (approved dose for women)
Frequency	As needed, at least 45 minutes before anticipated sexual activity
Duration	Maximum 8 doses per month (per approved labeling)
Notes	Vyleesi is FDA-approved for HSDD in premenopausal women. Use is on-demand, not daily. Not approved for use in men or postmenopausal women. Should be prescribed by a healthcare professional familiar with the medication.

Administration Routes

Routes studied in research settings (educational only):

Subcutaneous injection (approved route)
Intranasal (studied but not approved due to blood pressure effects)

Half-Life	Stability
Approximately 2.7 hours	Commercial product (Vyleesi) has defined stability per manufacturer specifications

Safety Profile & Known Risks

Commonly Reported Side Effects

Nausea (40% in trials, often diminishes with use)
Flushing
Injection site reactions
Headache
Transient blood pressure increase

Rare Risks & Concerns

Focal hyperpigmentation (darkening of skin, gums, or breast)
Severe hypotension in certain patients
Severe nausea requiring antiemetics

Contraindications

Uncontrolled hypertension
Cardiovascular disease
Concurrent use of naltrexone (drug interaction)
Pregnancy (Category X)
Breastfeeding

UK & EU Regulatory Context

🇬🇧 United Kingdom

Not approved. Available only through specialist channels or as research compound.

🇪🇺 European Union

Not approved by EMA. Not available as licensed medicine.

PT-141 (bremelanotide/Vyleesi) is FDA-approved in the United States for HSDD in premenopausal women since 2019. It is not approved in UK or EU. WADA prohibits its use in competitive sport.

Clinical Studies Summary

An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist.

This preliminary evaluation suggests the potential for bremelanotide to positively affect desire and arousal in women with female sexual arousal disorder and indicates that bremelanotide is a promising candidate for further evaluation in an at-home study.

J Sex Med. 2006View on PubMed

Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response.

Co-administration of intranasal PT-141 and a phosphodiesterase type 5 inhibitor may constitute a treatment alternative for patients in whom higher doses of a single therapy are not effective or well tolerated.

Urology. 2005View on PubMed

Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction.

Flushing and nausea were the most common adverse events reported in both studies and no clinically significant changes in vital signs, laboratory tests, ECGs, or physical exams were observed. Based upon its erectogenic potential and tolerability profile, PT-141 is a promising candidate for further evaluation as a treatment for male ED.

Int J Impot Res. 2004View on PubMed

Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra.

PT-141 was safe and well tolerated in both studies. The erectogenic potential of PT-141, its tolerability profile and its ability to cause significant erections in patients who do not have an adequate response to a PDE5 inhibitor suggest that PT-141 may provide an alternative treatment for ED with a potentially broad patient base.

Int J Impot Res. 2004View on PubMed

Gateways to clinical trials.

Com. This issue focuses on the following selection of drugs: Abetimus sodium, ademetionine, agalsidase alfa, agalsidase beta, alemtuzumab, alfimeprase, AMG-162, androgel, anidulafungin, antigastrin therapeutic vaccine, aripiprazole, atomoxetine hydrochloride; Bazedoxifene acetate, bevacizumab, bosentan; Caldaret hydrate, canfosfamide hydrochloride, choriogonadotropin alfa, ciclesonide, combretastatin A-4 phosphate, C…

Methods Find Exp Clin Pharmacol. 2004View on PubMed

PT-141: a melanocortin agonist for the treatment of sexual dysfunction.

Administration of PT-141 to normal men and to patients with erectile dysfunction resulted in a rapid dose-dependent increase in erectile activity. The results suggest that PT-141 holds promise as a new treatment for sexual dysfunction.

Ann N Y Acad Sci. 2003View on PubMed

Registered Trials & Regulatory Status

Registered trials

Currently recruiting

Furthest phase

Phase 4

Approved product

5 of 9 completed trials have never posted results. Unreported trials are not neutral: results that go unpublished are more often negative ones.

Single Dose of Vyleesi in Lactating Female Subjects to Measure the Concentration of Bremelanotide in Breast Milk

PHASE4

Status: Completed · 10 participants · Cosette Pharmaceuticals, Inc.

Conditions: Lactating Mother

No results postedNCT06867835

A Phase 2 Study Evaluating the Co-Administration of Bremelanotide With Tirzepatide for the Treatment of Obesity

PHASE2

Status: Active Not Recruiting · 108 participants · Palatin Technologies, Inc

Conditions: Obesity

No results postedNCT06565611

A Phase IIb, Multicenter, Open-Label, Prospective Study of Bremelanotide in Diabetic Kidney Disease

PHASE2

Status: Completed · 16 participants · Palatin Technologies, Inc

Conditions: Kidney Disease

No results postedNCT05709444

A Phase 3, Bridging, Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group Trial to Evaluate the Efficacy and Safety of Subcutaneously Administered Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder (With or Without Decreased Arousal)

PHASE3

Status: Completed · 193 participants · Kwang Dong Pharmaceutical co., ltd.

Conditions: Hypoactive Sexual Desire Disorder

No results postedNCT04943068

Role of the Melanocortin-4 Receptor in Hypoactive Sexual Desire Disorder

PHASE4

Status: Completed · 40 participants · Imperial College Healthcare NHS Trust

Conditions: Hypoactive Sexual Desire Disorder

Results postedNCT04179734

Study to Evaluate Rate of Nausea in Healthy Premenopausal Female Subjects Treated With Single Dose of Bremelanotide Alone or With Zofran

PHASE1

Status: Completed · 228 participants · AMAG Pharmaceuticals, Inc.

Conditions: Nausea

No results postedNCT03973047

2. Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder

PHASE3

Status: Completed · 714 participants · Palatin Technologies, Inc

Conditions: Hypoactive Sexual Desire Disorder

Results postedNCT02338960

1. Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder

PHASE3

Status: Completed · 723 participants · Palatin Technologies, Inc

Conditions: Hypoactive Sexual Desire Disorder

Results postedNCT02333071

Bremelanotide in Premenopausal Women With Female Sexual Arousal Disorder and/or Hypoactive Sexual Desire Disorder

PHASE2

Status: Completed · 612 participants · Palatin Technologies, Inc

Conditions: Female Sexual Arousal Disorder, Hypoactive Sexual Desire Disorder

Results postedNCT01382719

Evaluate the Safety and Efficacy of Bremelanotide in Women With Female Sexual Arousal Disorder (FSAD)

PHASE2

Status: Completed · Palatin Technologies, Inc

Conditions: Sexual Arousal Disorder

No results postedNCT00425256

Adverse event reports (FDA FAERS)

Not applicable: no licensed product contains this peptide, so it is not reported through FAERS. This is an absence of surveillance, not evidence of safety.

Source: ClinicalTrials.gov and openFDA. Updated automatically.

Looking for PT-141?

Source research-grade PT-141 from a trusted UK supplier — third-party tested with certificate of analysis.

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Frequently Asked Questions

Questions to ask a qualified clinician about PT-141

These are starter questions you can adapt for a GP, specialist, pharmacist, or anti-doping advisor. The aim is to help you have a better-informed conversation — not to replace one.

Is PT-141 / bremelanotide licensed in the UK?
What licensed UK alternatives exist for the sexual-health concern I'm asking about?
Do I have cardiovascular risk factors that would make bremelanotide unsuitable?
If accessed privately, what is the supply-chain provenance?

Quick Facts

Overview

01Evidence snapshot

02Human evidence grade

03Preclinical evidence grade

04Regulatory status

05Approved medical uses

06Unapproved / promotional claims

07Common internet claims

08Claim vs evidence

09Safety uncertainty score

10Known adverse signals

11Drug-interaction uncertainty

12Anti-doping status

13UK legal position

14EU legal position

15What this page cannot tell you

16Last reviewed

17Citation quality score

18Research gaps

19Safer alternatives / established care pathways

20Doctor discussion prompts

Questions to ask a qualified clinician

Discovery & History

Mechanism of Action

Researched Benefits

Claim vs Evidence

Theoretical Dosing & Protocols

Administration Routes

Safety Profile & Known Risks

Commonly Reported Side Effects

Rare Risks & Concerns

Contraindications

UK & EU Regulatory Context

🇬🇧 United Kingdom

🇪🇺 European Union

Clinical Studies Summary

An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist.

Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response.

Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction.

Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra.

Gateways to clinical trials.

PT-141: a melanocortin agonist for the treatment of sexual dysfunction.

Registered Trials & Regulatory Status

Single Dose of Vyleesi in Lactating Female Subjects to Measure the Concentration of Bremelanotide in Breast Milk

A Phase 2 Study Evaluating the Co-Administration of Bremelanotide With Tirzepatide for the Treatment of Obesity

A Phase IIb, Multicenter, Open-Label, Prospective Study of Bremelanotide in Diabetic Kidney Disease

A Phase 3, Bridging, Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group Trial to Evaluate the Efficacy and Safety of Subcutaneously Administered Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder (With or Without Decreased Arousal)

Role of the Melanocortin-4 Receptor in Hypoactive Sexual Desire Disorder

Study to Evaluate Rate of Nausea in Healthy Premenopausal Female Subjects Treated With Single Dose of Bremelanotide Alone or With Zofran

2. Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder

1. Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder

Bremelanotide in Premenopausal Women With Female Sexual Arousal Disorder and/or Hypoactive Sexual Desire Disorder

Evaluate the Safety and Efficacy of Bremelanotide in Women With Female Sexual Arousal Disorder (FSAD)

Adverse event reports (FDA FAERS)

Looking for PT-141?

Frequently Asked Questions

What is PT-141 approved for?

Does PT-141 work for men?

How is PT-141 different from Viagra?

Is PT-141 available in the UK?

Questions to ask a qualified clinician about PT-141

UK regulatory & safety context

Are peptides legal in the UK?

Unlicensed peptide risks

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