PT-141
Bremelanotide, a synthetic cyclic peptide that acts on melanocortin receptors in the central nervous system. Evidence includes animal pharmacology and controlled human trials in a defined adult clinical population.
Last reviewed September 22, 2026
The short version
PT-141 is another name used for bremelanotide, a lab-made cyclic peptide related to alpha-melanocyte-stimulating hormone. It activates melanocortin receptors involved in central nervous-system signaling. Research includes animal studies, early human pharmacology and large randomized trials in premenopausal women with a specific diagnosed sexual-health disorder.
An FDA-approved bremelanotide injection exists for that narrow indication and population. A compounded PT-141 preparation is not FDA-approved, and the approved evidence cannot be generalized to every person or use. A licensed provider makes the individual decision.
What it is
PT-141 is the research code for bremelanotide, a synthetic cyclic heptapeptide related to the human melanocortin peptide alpha-MSH. It is designed mainly as an agonist at melanocortin-3 and melanocortin-4 receptors in the central nervous system. It is not a reproductive hormone, testosterone or a phosphodiesterase inhibitor, and it does not work through the same pathway as those drug classes.
Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, with a lactam bridge joining side chains in the ring. The molecular formula is C50H68N14O10, molecular weight is 1,025.2 daltons and CAS number is 189691-06-3.
Where the research stands
Bremelanotide has a conventional development record for one defined indication, including animal mechanism work and controlled human trials. The evidence is population- and product-specific. It does not establish safety or benefit for men, postmenopausal women, other conditions or a compounded preparation.
How far the evidence has climbed
- Cell studiesYesMelanocortin-receptor pharmacology
- Animal studiesYesRodent and nonhuman-primate models
- Small human pilotsYesEarly human pharmacology studies
- Controlled human trialsYesA separate approved product in a defined population
- Compounded preparationNot approvedA separate FDA-approved product exists
Here is what selected studies looked at. Each names its species or population because the findings cannot be generalized beyond them.
Early melanocortin pharmacology
A development paper combined rat, nonhuman-primate and early male human observations and linked PT-141 activity to central melanocortin receptors. Those early data did not establish an approved indication.1
Behavioral specificity in rats
A female-rat study measured distinct courtship-related behaviors and general movement. The result was an animal mechanism finding, not a human clinical outcome.2
Two phase 3 trials
Two randomized trials enrolled 1,267 premenopausal women with acquired, generalized hypoactive sexual desire disorder and measured desire and distress scores against placebo. They did not test compounded PT-141.3
Open-label extension
An extension enrolled 684 women and measured safety and clinical endpoints, including treatment-related events. It did not test a compounded preparation or another population.4
Brain-imaging crossover study
A randomized crossover study in 31 premenopausal women with the diagnosed disorder used functional MRI to measure task-related brain processing. It did not test compounded PT-141 or other populations.5
What the research can’t tell you
Approval is population-specific
The controlled program concerned premenopausal women with acquired, generalized hypoactive sexual desire disorder. It does not establish an outcome for men, postmenopausal women or people without that diagnosis.3
Compounded is not the approved product
Evidence for the FDA-approved injection does not verify the quality, stability or clinical performance of a compounded PT-141 preparation.
Common adverse effects matter
In the longer study, nausea, flushing and headache were the most common treatment-related events.4
Blood pressure is a labeled risk
The approved label warns about transient blood-pressure increases and identifies cardiovascular conditions for which the product is contraindicated.6
Pigmentation can occur
Melanocortin receptors also participate in pigment biology. The label reports focal darkening with repeated use, which may not fully resolve.6
Longer follow-up is still bounded
An open-label extension adds information but does not provide the same protection against bias as a blinded comparison or settle very rare harms.4
FDA status
Approved product exists for one indication; compounded PT-141 is not FDA-approved
FDA approved a bremelanotide injection in 2019 for acquired, generalized hypoactive sexual desire disorder in premenopausal women. The label does not approve it for men, postmenopausal women or other indications.6
A compounded PT-141 preparation is not the FDA-approved finished product. Any prescribing decision through Promise’s platform belongs to a licensed provider. FDA states that it does not verify compounded drugs for safety, effectiveness or quality before marketing.7
Promise Peptides is currently taking waitlist sign-ups. Joining is not a medical request and no prescription comes from it.
A prescription route
Promise is currently accepting waitlist signups. Joining is not a treatment request and does not result in a prescription. If treatment visits open, any treatment request would require clinical review; prescribing and pharmacy fulfillment would remain separate decisions.
Start on Promise’s PT-141 page
It shows what the treatment involves and its current availability.
Answer the PT-141 questionnaire
A licensed provider reviews health history, medicines and goals, and can decline. Not everyone qualifies.
Pharmacy review is a separate step
A prescription does not guarantee preparation or dispensing. A pharmacy must separately determine whether it can fulfill the prescription under the applicable requirements.
A prescription does not make compounded PT-141 FDA-approved or extend the approved indication to another person or population; it reflects an individualized clinical decision.
PT-141 at Promise
Read the treatment information and view the current waitlist.
Join the Promise waitlistPeak may earn money when readers become Promise patients.
Joining does not guarantee future treatment availability. Availability would depend on the treatment, state, clinical review and separate pharmacy review.
Questions
Is PT-141 the same as bremelanotide?
PT-141 is the research code commonly used for bremelanotide. A product’s regulatory status still depends on whether it is the approved finished drug or a compounded preparation.
What receptors does PT-141 act on?
It acts mainly as an agonist at melanocortin-3 and melanocortin-4 receptors, with central nervous-system signaling central to its pharmacology.1
Sources
- Molinoff PB, et al. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Ann N Y Acad Sci. 2003;994:96-102. PubMed 12851303
- Pfaus J, et al. Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist. Proc Natl Acad Sci U S A. 2004;101:10201-10204. PubMed 15226502
- Kingsberg SA, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstet Gynecol. 2019;134:899-908. PubMed 31599840
- Simon JA, et al. Long-term safety and efficacy of bremelanotide for hypoactive sexual desire disorder. Obstet Gynecol. 2019;134:909-917. PubMed 31599847
- Thurston L, et al. Melanocortin 4 receptor agonism enhances sexual brain processing in women with hypoactive sexual desire disorder. J Clin Invest. 2022;132:e152341. PubMed 36189794
- DailyMed. Bremelanotide injection label. Published November 18, 2025.
- U.S. Food and Drug Administration. Compounding and the FDA: Questions and Answers.