What is PT-141?
PT-141 is a cyclic heptapeptide (circular-shaped and contains 7 amino acids) that works as a melanocortin receptor agonist. It is FDA approved for the treatment of hypoactive sexual desire disorder in women, but is used off-label and in research settings in both men and women to increase libido and sexual desire.
How Does PT-141 Work?
PT-141 is a melanocortin receptor agonist. There are five main melanocortin receptors (MC1R-MC5R). MC1R is associated with melanogenesis and increased skin pigmentation, whereas MC3R and MC4R work to increase libido and have a role in energy balance and appetite suppression. Other peptides that affect the melanocortin receptor pathway include melanotan I (selective MC1R receptor) and melanotan II (nonselective, binds to MC1R to increase skin pigmentation and to other receptors, including MC3R and MC4R).
PT-141 has demonstrated modest but statistically significant improvements in sexual desire in clinical trials of women with hypoactive sexual desire disorder. It achieves this effect primarily through binding MC4R and MC3R. As a result, it increases responsiveness to sexual cues. PT-141 also binds to other melanocortin receptors, including MC1R, and therefore has the secondary effect of increasing skin pigmentation.
What is PT-141 Used For?
- Increasing sexual desire, especially in individuals with low libido
- Increasing skin pigmentation (tanning): Minor role, mostly a side effect
- Appetite suppression and energy balance: Minor role, mostly a side effect
Side Effects of PT-141
While generally well-tolerated, PT-141 is associated with increased blood pressure (average increase of 6 mmHg systolic and 3 mmHg diastolic) and increased heart rate. These symptoms are present 2-4 hours after dosing.
As with all injectables, injection site reactions and allergic reactions to the peptide or formulation excipients are possible.
PT-141 Dosing Protocol (for Research)
PT-141 is taken up to one hour prior to expected sexual activity, with peak effect lasting for up to 3-5 hours.
| Phase | Dose & frequency |
|---|---|
| 1.75 mg | injected subcutaneously 45 minutes - 1 hour before anticipated sexual activity |
Shown for education. A licensed clinician should set any actual dose. Compare protocols across peptides in the peptide dosage chart.
Common questions about PT-141 (bremelanotide)
What is PT-141 (bremelanotide)?
PT-141 is a cyclic heptapeptide (circular-shaped and contains 7 amino acids) that works as a melanocortin receptor agonist. It is FDA approved for the treatment of hypoactive sexual desire disorder in women, but is used off-label and in research settings in both men and women to increase libido and sexual desire.
What is PT-141 (bremelanotide) used for?
Areas studied include: Increasing sexual desire; Increasing skin pigmentation (tanning); Appetite suppression and energy balance.
How does PT-141 (bremelanotide) work?
PT-141 is a melanocortin receptor agonist. There are five main melanocortin receptors (MC1R-MC5R). MC1R is associated with melanogenesis and increased skin pigmentation, whereas MC3R and MC4R work to increase libido and have a role in energy balance and appetite suppression.
What are the side effects of PT-141 (bremelanotide)?
While generally well-tolerated, PT-141 is associated with increased blood pressure (average increase of 6 mmHg systolic and 3 mmHg diastolic) and increased heart rate. These symptoms are present 2-4 hours after dosing.
What is the dosage of PT-141 (bremelanotide)?
One commonly referenced research protocol is: 1.75 mg injected subcutaneously 45 minutes - 1 hour before anticipated sexual activity. Shown for education only; a licensed clinician should set any actual dose. See the dosing table.
How do you mix (reconstitute) PT-141 (bremelanotide)?
Wipe the vial tops with alcohol, add bacteriostatic water slowly so it runs down the inside of the glass, then roll the vial gently until the powder dissolves; don’t shake it. See the step-by-step guide with diagrams for the pen and syringe methods.
How much bacteriostatic water do you add to PT-141 (bremelanotide)?
There is no single correct amount. We recommend 2.1 mL: about 0.1 mL is lost during transfer, leaving roughly 2.0 mL of usable solution. You can add more or less (most peptide vials hold up to 3 mL); just enter the amount in the dose calculator. See the step-by-step mixing guide.
Is PT-141 (bremelanotide) FDA-approved?
PT-141 (bremelanotide) is FDA-approved in the US for specific indications (status as of October 2026).
References
- Kingsberg SA, et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstet Gynecol. 2019 Nov;134(5):899-908. View source
- Safarinejad MR, Hosseini SY. Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study. J Urol. 2008 Mar;179(3):1066-71. View source