Compound record · Sexual health
PT-141 (bremelanotide)
Also Bremelanotide · Vyleesi · PT141 · PT 141 · Rekynda
Melanocortin-4 receptor agonist
FDA-approved on-demand injection for low sexual desire in premenopausal women
Record reviewed 1 September 2026 · 5 references
In the AERVYN range
1 pen carries PT-141 (bremelanotide)
- Class
- Melanocortin-4 receptor agonist (α-MSH analogue)
- Route
- 1.75 mg subcutaneous autoinjector, as needed (≤ 8 doses/month)
- Trial participants
- 1,247 women in RECONNECT phase 3
- Licensed effect
- Desire score +0.3–0.4 vs placebo (1.2–6 scale); nausea in 40%
- Prescription
- US only (FDA 2019); not authorised in UK, EU, AU, CA
01 Overview
What PT-141 (bremelanotide) is
Summary
Bremelanotide is a cyclic peptide analogue of the hormone α-MSH that activates melanocortin receptors in the brain. Under the brand Vyleesi it has been FDA-approved since June 2019 for premenopausal women with acquired, generalised hypoactive sexual desire disorder, taken as a 1.75 mg subcutaneous autoinjector shortly before anticipated sexual activity. Two 24-week phase 3 trials in 1,247 women showed statistically significant but modest gains in desire, with nausea in about 40% of users. It is not authorised in the UK, EU, Australia or Canada and is not licensed for men.
Mechanism
Activates melanocortin-4 (and to a lesser extent MC1 and MC3) receptors. In the hypothalamus this is thought to shift the balance of dopamine and other neurotransmitters towards sexual excitation rather than inhibition. MC1 activation in skin explains the pigmentation side effect, and central melanocortin activity explains the transient rise in blood pressure and fall in heart rate.
02 Evidence by goal
What has been shown, for which goal
Grades follow one scale across the site. Moderate overall means: at least one well-conducted randomised trial or consistent controlled human studies.
Sexual health
ModerateIn premenopausal women with HSDD (RECONNECT, n = 1,247) desire scores rose by 0.5–0.6 points versus 0.2 with placebo on a 1.2–6 scale over 24 weeks, with a matching small fall in distress — statistically significant but modest, and 18% stopped because of side effects. In men, small phase 2 studies of intranasal and subcutaneous bremelanotide produced erections in erectile dysfunction, but the programme was discontinued after blood-pressure concerns; it is not authorised for men or for postmenopausal women.
Weight management
InsufficientMelanocortin-4 receptor activation suppresses appetite in animals and reduced appetite is reported by some users, but bremelanotide has never been studied for weight and is not indicated for it.
Skin & cosmetic
InsufficientBremelanotide is sometimes misused for tanning because it darkens skin; in trials this appeared as focal, patchy hyperpigmentation of the face, gums and breasts that did not always resolve — an adverse effect, not a cosmetic benefit.
03 Regulatory status
Where it is authorised, and for what
Status is recorded per jurisdiction from regulator sources and reviewed by hand. It is never inferred from another region's decision.
United Kingdom
Not authorisedNo MHRA marketing authorisation; not available on the NHS.
Bremelanotide has not been licensed in the UK. Products sold online as 'PT-141' are unlicensed medicines of unknown origin.
04 Dosing research
What the evidence says about exposure
Published human studies and the doses, routes and durations they used — reported as research information, not a recommendation.
Research information — not a recommendation. These are the exposures used in published human studies, reported so you can see what has been tested. They are not dosing instructions and do not apply to any individual.
Study 01
RECONNECT — two identical phase 3 trials of as-needed bremelanotide in premenopausal women with HSDD
Kingsberg SA et al., Obstet Gynecol 2019;134:899–908 (Studies 301 and 302)
- Design
- Randomised, double-blind, placebo-controlled (two identical trials)
- Population
- Premenopausal women (mean age 39) with acquired, generalised HSDD for at least six months
- Participants
- n = 1,247
- Duration
- 24 weeks (followed by a 52-week open-label extension)
- Route
- Subcutaneous injection
- Doses studied
- 1.75 mg subcutaneous via autoinjector, self-administered as needed about 45 minutes before anticipated sexual activity; maximum one dose per 24 hours (trials allowed up to 12 doses per month; the label recommends no more than 8). Median 10 doses over 24 weeks.
- Outcome at this exposure
- FSFI desire-domain score rose 0.5 (Study 1) and 0.6 (Study 2) points versus 0.2 with placebo (scale 1.2–6.0; p ≤ 0.0002); distress score (FSDS-DAO item 13) fell 0.7 versus 0.4 points in both studies. Effects were statistically significant but small in absolute terms.
- Adverse events observed
- Nausea 40% (versus 1% placebo; 13% needed anti-emetics, 8% stopped), flushing 20%, injection-site reactions 13%, headache 11%, vomiting 5%. Discontinuation for adverse reactions 18% versus 2%. Transient blood-pressure rise of up to 6/3 mmHg with heart-rate fall of up to 5 bpm after each dose; focal hyperpigmentation in 1%.
Study 02
RECONNECT open-label extension — 52-week safety
Simon JA et al., Obstet Gynecol 2019;134:909–917
- Design
- Uncontrolled, open-label continuation of the two phase 3 trials
- Population
- Women completing the 24-week double-blind phase who chose to continue
- Participants
- n = 684
- Duration
- 52 weeks
- Route
- Subcutaneous injection
- Doses studied
- 1.75 mg subcutaneous as needed (median 12 doses over the year)
- Outcome at this exposure
- Improvements in desire and distress were maintained; no new efficacy signal beyond the controlled phase.
- Adverse events observed
- Adverse-event profile matched the controlled phase (nausea, flushing, headache). One case of acute hepatitis with transaminases over 40 times normal after 10 doses in a year, resolving four months after stopping — the drug could not be excluded as the cause.
Study 03
Early-phase intranasal bremelanotide in men with erectile dysfunction (development discontinued)
Diamond LE et al., Int J Impot Res 2004;16:51–59
- Design
- Randomised, double-blind, placebo-controlled, dose-ranging
- Population
- Healthy men and men with mild-to-moderate erectile dysfunction
- Participants
- Not reported
- Duration
- Single doses
- Route
- Intranasal
- Doses studied
- Single intranasal doses (dose-ranging); the intranasal formulation was later abandoned because of blood-pressure increases
- Outcome at this exposure
- Dose-related erectile responses on RigiScan monitoring compared with placebo; the finding of increased desire led to the later HSDD programme in women.
- Adverse events observed
- Nausea, flushing and yawning; blood-pressure increases at higher doses drove the decision to stop intranasal development.
The only authorised regimen is 1.75 mg subcutaneously as needed, with at most one dose in 24 hours and eight doses per month; pre-treatment with ondansetron did not reduce nausea in a phase 4 study. Higher or daily dosing increases hyperpigmentation and the time spent with raised blood pressure. Vials and nasal sprays sold online as 'PT-141' are not the approved product and their content is unverified.
05 Safety
Adverse effects and contraindications
Common effects seen in trials or reports, serious effects that warrant urgent review, and conditions under which use is not appropriate or needs assessment.
Common adverse effects
- Nausea (about 40%; usually improves after the first or second dose)
- Flushing (about 20%)
- Injection-site pain, bruising or redness (about 13%)
- Headache (about 11%)
- Vomiting (about 5%)
- Cough, fatigue, hot flush, dizziness, nasal congestion (2–3%)
- Reduced appetite
Serious adverse effects
- Transient rise in blood pressure (up to 6/3 mmHg) and fall in heart rate after every dose — a cardiovascular risk with frequent use
- Focal hyperpigmentation of face, gums or breasts that may not fully resolve (1% with up to 8 doses a month; 38% with daily dosing; more common in darker skin)
- Severe nausea requiring anti-emetics or discontinuation
- Acute hepatitis (single case in the extension study; causality not excluded)
- Severe headache requiring hospital care (single case)
- Reduced absorption of oral medicines, including treatment failure of oral naltrexone
Contraindications
- High blood pressureDo not use
Contraindicated in uncontrolled hypertension. Each dose raises systolic blood pressure by up to 6 mmHg for several hours; even controlled hypertension requires a prescriber to confirm control before and during use.
- Cardiovascular diseaseDo not use
Contraindicated with known cardiovascular disease and not recommended at high cardiovascular risk, because of the repeated transient rise in blood pressure and fall in heart rate.
- Kidney diseaseCaution
Use with caution in severe renal impairment (eGFR below 30), where nausea and vomiting are more frequent and severe.
- Liver diseaseCaution
Not evaluated in severe hepatic impairment; a single case of acute hepatitis occurred in the extension study.
- Melanoma or atypical molesCaution
Not addressed in the label, but bremelanotide also activates the MC1 receptor on pigment cells (causing focal hyperpigmentation); a history of melanoma or atypical moles is worth raising with a dermatologist first.
- Mental health conditionCaution
The licence covers low desire that is not due to a psychiatric condition or to medicines such as antidepressants; those causes need assessment before treatment is considered.
- Hormonal disorderCaution
Low desire caused by a medical condition (for example thyroid or pituitary disorders, or the menopause) is outside the licence and should be investigated first; the medicine is not indicated after the menopause.
Do not use = should not be used · Caution = needs assessment
06 Interactions
Medicine classes that need review
Grouped by how seriously the combination should be taken. Class labels match the medicines questionnaire in the assessment.
- Major
- Moderate
- Minor
Major
Combination should be reviewed by a prescriber before use.
Other / not sure
Oral naltrexone (for alcohol or opioid dependence): bremelanotide can markedly reduce its absorption, risking treatment failure — the label advises avoiding the combination.
Moderate
Monitoring or dose review is usually advised.
Narrow-therapeutic-index medicine
Lithium, digoxin, ciclosporin
Bremelanotide slows gastric emptying and can reduce the rate and extent of absorption of oral medicines that depend on reaching a threshold concentration.
Antibiotic
Amoxicillin, doxycycline
The label advises avoiding bremelanotide while taking oral antibiotics whose effect depends on reaching threshold blood levels.
Blood pressure medicine
Ramipril, amlodipine, losartan
Blood pressure must be controlled before use and checked periodically; the transient post-dose rise adds to whatever the antihypertensive is managing.
Beta blocker
Bisoprolol, propranolol, atenolol
Bremelanotide lowers heart rate by up to 5 bpm for several hours after each dose; combined with a beta blocker this may be noticeable.
GLP-1 / incretin medicine
Ozempic, Wegovy, Mounjaro, Saxenda
Both slow gastric emptying and cause nausea; the combination has not been studied and may be poorly tolerated.
Minor
Generally compatible; awareness is sufficient.
Anti-inflammatory painkiller
Ibuprofen, naproxen, diclofenac
Delayed absorption can postpone the effect of oral painkillers such as indomethacin when rapid onset is wanted.
Antidepressant
Sertraline, fluoxetine, venlafaxine, mirtazapine
Not a pharmacological interaction, but antidepressant-induced low desire is excluded from the licensed indication and should be addressed with the prescriber first.
07 Pregnancy & breastfeeding
Status in pregnancy
The label advises effective contraception during use and stopping if pregnancy is suspected; animal studies showed fetal harm at high exposures and a pregnancy registry is in place. It is not known whether bremelanotide passes into breast milk.
08 Monitoring
What is usually monitored
Parameters that trials and product information track. A clinician decides what applies to an individual.
- 01Blood pressure and heart rate before starting and periodically during use
- 02Number of doses per month (no more than eight) and spacing (at least 24 hours)
- 03Skin, gums and breasts for new patches of darkening
- 04Nausea, vomiting and hydration, especially in the first doses
- 05Timing of oral medicines relative to injections
- 06Contraception and pregnancy status
- 07Whether desire and distress have meaningfully changed after around eight weeks of use
09 Combinations
What is known about combining it
Notes on pairing with other compounds in the directory: whether the combination has been studied in people, and where mechanisms overlap.
Kisspeptin
No human studies
Overlap · Both act centrally on sexual-desire pathways in the brain.
No study has combined them. Kisspeptin is investigational and given by infusion in research settings only; there is no rationale for combining it with an approved on-demand medicine.
Melanotan II
No human studies
Overlap · Both are melanocortin agonists — bremelanotide is a metabolite of Melanotan II — so the mechanism is duplicated.
Combining them stacks the same receptor activity, with additive nausea, blood-pressure rise, pigmentation and (in men) prolonged-erection risk, and adds an unregulated product to a prescription one.
Semaglutide
No human studies
Overlap · Both slow gastric emptying and commonly cause nausea.
No data on combined use; tolerability may be worse and absorption of oral medicines may be further delayed.
Tirzepatide
No human studies
Overlap · Both slow gastric emptying and commonly cause nausea.
No data on combined use; tolerability may be worse and absorption of oral medicines may be further delayed.
Gonadorelin
No human studies
Overlap · Both are sold for sexual health, but PT-141 acts on brain melanocortin receptors while gonadorelin acts on the hormonal axis.
No study has combined them. They address different problems — desire versus hormonal signalling — and there is no rationale or safety data for using both.
Discuss any proposed combination with a qualified healthcare professional.
10 Source considerations
Supply, quality and legitimacy
How the compound reaches people in practice, and what that means for product quality.
- 01In the United States the only legitimate product is the Vyleesi prescription autoinjector; elsewhere no authorised product exists at all.
- 02Vials, pre-filled pens and nasal sprays sold online as 'PT-141' are unapproved, with no assurance of identity, dose, sterility or endotoxin content; nasal formulations were abandoned in development because of blood-pressure effects.
- 03Compounded bremelanotide is not the approved product and has not been shown to be equivalent.
- 04Because bremelanotide is a close relative of Melanotan II, mislabelled or cross-contaminated products are a realistic concern.
11 Questions for your clinician
Take these to your appointment
Specific to this compound. The personal assessment adds questions drawn from your own history and medicines.
- 01Do I meet the licensed definition — premenopausal, acquired and generalised low desire that is not explained by another condition, a medicine or relationship factors?
- 02Is my blood pressure and cardiovascular risk low enough for a medicine that raises blood pressure after every dose?
- 03How should I handle nausea, and when would we decide it is not working?
- 04Which of my oral medicines could be affected by slowed stomach emptying?
- 05What is my contraception plan, and what should I do if I become pregnant?
- 06Are there non-drug approaches or other licensed options worth considering first?
The personal assessment tailors this list to your responses.
12 References
Sources behind this record
Regulator documents and peer-reviewed publications used to derive every grade and statement above.
- 01Vyleesi (bremelanotide injection) US Prescribing Information — DailyMed
- 02FDA news release — FDA approves new treatment for hypoactive sexual desire disorder in premenopausal women (21 June 2019)
- 03Kingsberg SA et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstet Gynecol 2019;134:899–908
- 04Simon JA et al. Long-term safety and efficacy of bremelanotide for hypoactive sexual desire disorder. Obstet Gynecol 2019;134:909–917
- 05Diamond LE et al. Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141 in healthy males and patients with mild-to-moderate erectile dysfunction. Int J Impot Res 2004;16:51–59
The Peptide Checkup provides educational information and a structured summary of published research and regulatory status. It is not medical advice, does not diagnose or treat any condition, and does not replace a consultation with a qualified healthcare professional.
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