Peptide library · Melanocortin agonist

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 October 8, 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

  1. Cell studiesYesMelanocortin-receptor pharmacology
  2. Animal studiesYesRodent and nonhuman-primate models
  3. Small human pilotsYesEarly human pharmacology studies
  4. Controlled human trialsYesA separate approved product in a defined population
  5. 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.

  • AnimalsHumans2003

    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

  • Female rats2004

    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

  • Humans2019

    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

  • Humans2019

    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

  • Humans2022

    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 prescribes PT-141 now through licensed U.S. providers. A provider reviews every request and decides; not everyone qualifies.

A prescription route

Promise prescribes PT-141 now. Here is the route to a licensed U.S. provider’s review; not everyone qualifies:

  1. Start on Promise’s PT-141 page

    The page has a visit-start link and a price. A request does not guarantee a prescription.

  2. Share your health information

    A licensed U.S. provider reviews every request, including health history, medicines and goals, and can decline. Not everyone qualifies.

  3. Pharmacy review is a separate step

    A prescription does not guarantee preparation or dispensing. A licensed U.S. compounding pharmacy must review whether it can fulfill the prescription under the applicable requirements. Compounded medications are not FDA-approved.

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

Start a visit request. A licensed U.S. provider reviews it and can decline.

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Start PT-141 visit

Peak may earn money when readers become Promise patients.

U.S. patients only. Availability varies by state and treatment. A licensed U.S. provider reviews every request; not everyone qualifies.

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

Is compounded PT-141 FDA-approved?

No. An approved bremelanotide product exists for one indication and population, but the compounded form is not FDA-approved.67

Sources

  1. 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
  2. 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
  3. 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
  4. Simon JA, et al. Long-term safety and efficacy of bremelanotide for hypoactive sexual desire disorder. Obstet Gynecol. 2019;134:909-917. PubMed 31599847
  5. 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
  6. DailyMed. Bremelanotide injection label. Published November 18, 2025.
  7. U.S. Food and Drug Administration. Compounding and the FDA: Questions and Answers.