Compounds / PT-141
PT-141
Also known as: Bremelanotide; Vyleesi; PT-141; Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH; CAS 189691-06-3
Primary research focus: Acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women
Last updated July 2026 · Reviewed against FDA labeling and published research.
What is PT-141?
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist that acts centrally on the brain pathways governing sexual desire, rather than peripherally on blood flow the way PDE5 inhibitors do. It is FDA-approved and marketed as Vyleesi for acquired, generalized hypoactive sexual desire disorder in premenopausal women, approved in June 2019. That indication is narrow and specific; the broader uses discussed online, including use in men, are off-label.
Bremelanotide is a non-selective melanocortin receptor agonist with preference for MC4R, activating melanocortin receptors in the hypothalamus and central nervous system that gate sexual motivation. It is thought to modulate dopaminergic pathways involved in sexual desire, though the approved labeling states the precise mechanism for its HSDD benefit is unknown. Because the mechanism is central, it addresses desire rather than the vascular mechanics of erection, which distinguishes it from PDE5 inhibitors. Its origins are notable: bremelanotide is essentially a refined metabolite of Melanotan II, developed after male volunteers in tanning studies reported spontaneous erections. Replacing the C-terminal amide of Melanotan II with a free acid shifted the profile toward sexual effects and away from pigmentation, though hyperpigmentation remains a dose-related concern.
How it’s supplied
Brand / trade names: Vyleesi
Supplied as the FDA-approved product Vyleesi: a 1.75 mg single-dose subcutaneous autoinjector for administration in the abdomen or thigh, used as needed at least 45 minutes before anticipated sexual activity, with no more than one dose in 24 hours and no more than 8 doses per month. Compounded PT-141 (including nasal sprays and vials) is also sold; those are not the FDA-approved product and have not been evaluated by the FDA for identity, purity, or potency.
Dosage Chart
Units shown are for a U-100 insulin syringe (100 units = 1 mL), calculated from the vial size and BAC water you select. Always confirm against your prescription and your syringe markings.
| Phase | Dose | Frequency | Notes |
|---|---|---|---|
| Weeks 1-8 | 500mcg | 1x Daily | — |
| Weeks 9-12 | 1mg | 1x Daily | — |
| Weeks 13-16 | 1.5mg | 1x Daily | — |
- Rotate injection sites to reduce irritation and lipohypertrophy
- Not for use during pregnancy or breastfeeding
- Do not exceed the recommended dose to try to speed results
- The FDA-approved on-demand regimen uses 1.75 mg subcutaneous before sexual intercourse (max 8 doses/month)
- Daily protocols at 2.5 mg have been studied in obese women for appetite and weight reduction, suggesting daily use can be tolerated
Potential Benefits and Side Effects
Effects reported in published research. Not a promise of results, and not medical advice.
- Established for the approved indication; other uses are off-label and less well supported.
- Improves sexual desire and reduces desire-related distress in premenopausal women with acquired, generalized HSDD.
- Acts centrally on desire rather than on vascular mechanics, addressing a different problem than PDE5 inhibitors.
- On-demand dosing rather than daily use, unlike flibanserin.
- Non-hormonal mechanism.
- Studied off-label in men for low libido and certain erectile dysfunction not fully responsive to PDE5 inhibitors.
- Per the approved labeling and the RECONNECT trials.
- Nausea (approximately 40 percent versus 1 percent on placebo; roughly 8 percent required antiemetics and 13 percent discontinued).
- Flushing (approximately 20 percent).
- Injection-site reactions (approximately 13 percent).
- Headache (approximately 11 percent).
- Vomiting, cough, fatigue, dizziness, and nasal congestion.
- Focal hyperpigmentation, which may be permanent, and transient blood-pressure increases with heart-rate reduction.
Warnings and contraindications
Important safety information. This is not exhaustive — read the full prescribing information and consult your prescriber or pharmacist.
- Based on the FDA-approved labeling for Vyleesi.
- Bremelanotide causes transient increases in blood pressure and reductions in heart rate after each dose; it is contraindicated in uncontrolled hypertension or known cardiovascular disease.
- It is not recommended in patients at high risk for cardiovascular disease.
- Nausea is the dominant adverse effect: in the Phase 3 RECONNECT trials about 40 percent of treated women had nausea versus 1 percent on placebo, roughly 8 percent required antiemetic treatment, and about 13 percent discontinued because of it.
- Focal hyperpigmentation (including on the face, gums, and breasts) can occur and may not fully resolve after stopping; risk is higher with more frequent dosing, and the 8-doses-per-month limit reflects this.
- Women should avoid pregnancy during use and discontinue if pregnancy occurs.
- It is approved only for premenopausal women with acquired, generalized HSDD; it is not indicated in postmenopausal women, in men, or to enhance sexual performance.
- Exceeding the labeled dose does not increase efficacy (the dose-response curve flattens) but does increase side effects.
- Per the approved labeling: uncontrolled hypertension, known cardiovascular disease, and known hypersensitivity to bremelanotide or any component. Use is not recommended in patients at high cardiovascular risk.
Reconstitution Steps
How to prepare the lyophilized vial. Confirm specifics with your pharmacist or prescriber.
- The FDA-approved product (Vyleesi) is a prefilled single-dose autoinjector and is NOT reconstituted. The steps below describe handling only; compounded PT-141 powder follows the pharmacy's directions.
- Confirm the product is the 1.75 mg bremelanotide autoinjector and check the expiration date.
- Wash your hands and inspect the window: the liquid should be clear and colorless to slightly yellow, with no particles.
- Select an injection site on the abdomen or thigh and clean it with an alcohol swab.
- Administer as directed by the labeling at least 45 minutes before anticipated sexual activity.
- Use no more than one dose in 24 hours and no more than 8 doses per month.
- Dispose of the used autoinjector in a sharps container.
- No dilution or concentration calculation applies to the approved autoinjector; the reconstitution calculator on this page does not apply to Vyleesi.
US regulatory status
Classifications are public record but can change. For reference only, not legal advice.
Development: Bremelanotide was developed by Palatin Technologies out of University of Arizona melanocortin research: Melanotan II, being studied as a sunless tanning agent, produced unexpected erections in male volunteers, and bremelanotide was refined from that chemistry to maximize sexual effects while reducing pigmentation. Palatin first pursued an intranasal formulation for erectile dysfunction, but that program was abandoned after blood-pressure increases were observed. The company pivoted to subcutaneous injection and to HSDD in premenopausal women, an indication with no approved drug at the time. The FDA approved Vyleesi in June 2019 on the strength of two identical Phase 3 trials (the RECONNECT program). Bremelanotide is one of two FDA-approved options for premenopausal HSDD, alongside flibanserin (Addyi), a daily oral agent with a different mechanism. Off-label use in men for low libido and erectile dysfunction is common under physician supervision but is not an approved indication and rests on earlier, smaller data.
Notes: PT-141 (bremelanotide) is FDA-approved as Vyleesi for acquired, generalized hypoactive sexual desire disorder in premenopausal women, and is available by prescription. That approval is narrow: use in men, in postmenopausal women, or for general sexual enhancement is off-label. Because bremelanotide is an approved drug substance, compounded preparations (including nasal sprays) can be prepared by 503A and 503B pharmacies under prescription, but compounded forms are not the FDA-evaluated product and dosing should follow the approved label where applicable. It is not a controlled substance. Note that PT-141 is derived from Melanotan II, which by contrast is approved nowhere and is restricted from compounding. (Status current as of mid-2026.)
International status
Pharmacokinetics
Storage and handling
Important Notes
Practical considerations for consistency and safety.
- PT-141 (bremelanotide) is a genuinely FDA-approved drug (Vyleesi), but the indication is narrow: acquired, generalized HSDD in premenopausal women only. Use in men is off-label.
- It works centrally on melanocortin (MC4R) pathways governing desire, not on blood flow like PDE5 inhibitors.
- It is derived from Melanotan II, but the two are not interchangeable: Melanotan II is approved nowhere and is restricted from compounding.
- Nausea is common and was the main reason for discontinuation in trials; the 8-doses-per-month cap exists to limit hyperpigmentation risk.
- It is contraindicated in uncontrolled hypertension or known cardiovascular disease because of transient blood-pressure increases.
Lifestyle Factors
- Dosed on demand at least 45 minutes before anticipated activity, with a cap of 8 doses per month.
- Caution with alcohol is advised given potential additive cardiovascular effects.
- Blood pressure should be controlled before use.
References
Related compounds
Important disclaimer
This page is an educational reference, not medical advice, a diagnosis, or a treatment recommendation, and not a substitute for your prescriber or pharmacist. Approval and regulatory status varies by compound and can change. Always confirm against current prescribing information and consult a qualified healthcare professional before making any decision about a medication.