How PT-141 Works: Mechanism and Pharmacology
How PT-141 works: its target and mechanism as the sources state them, how long it acts, and what is still unknown.
- Class
- Melanocortin agonist
- FDA status
- Approved for HSDD (Vyleesi)
- Routes studied
- subcutaneous; intranasal
- Half-life
- approximately 2.7 hours (range 1.9-4.0 h)
- subcutaneous, in people · FDA label (Vyleesi)
How long it acts
Half-life values from FDA labels and published studies, by route. Animal values are labelled and do not describe people.
| Route | Half-life | Measured in | Source |
|---|---|---|---|
| subcutaneous | approximately 2.7 hours (range 1.9-4.0 h) | People | FDA label (Vyleesi) |
| intranasal | mean t1/2 1.85 to 2.09 h | People | International journal of impotence research 2004, PMID 14963471 |
| As labelled | approximately 2.7 hours (range 1.9-4.0 h), single subcutaneous dose | People | FDA label (Vyleesi) |
Full detail, including drug-testing windows, is on the PT-141 half-life page.
Which receptors it binds, per the label
The label describes bremelanotide as a melanocortin receptor agonist that activates several subtypes without selectivity, listing an order of potency among MC1R, MC4R, MC3R, MC5R and MC2R.[1]
The same label section says plainly that how the drug improves low desire in women is not known.[1]
How the research papers describe it
A study abstract describes it as a synthetic analog of alpha-melanocyte-stimulating hormone acting as an agonist at the MC3R and MC4R receptors.[3]
A blood-pressure study notes that melanocortin agonists binding the MC4R receptor may cause increases in blood pressure, and it measured blood pressure in women given bremelanotide.[4]
An early male study describes PT-141 as a cyclic heptapeptide melanocortin analog, a seven-amino-acid ring.[5]
What happens in the body after a dose
Per the label, each dose transiently raises blood pressure and lowers heart rate.[1]
The label puts the largest measured pressure rises at 6 mmHg systolic and 3 mmHg diastolic.[1]
How long it stays in the body and how often it can be used
The label gives a mean terminal half-life of about 2.7 hours after one subcutaneous dose.[1]
Consecutive doses within 24 hours are untested for efficacy and may add to blood-pressure effects, so the label sets a limit on frequency.[1]
What is unknown
Of the 9 abstracts cited on this page for mechanism, none identifies how receptor binding produces the change in desire, which the label itself calls unknown.
Calculated from mechanism abstracts 9; label states mechanism unknown yes. Formula: abstracts explaining desire mechanism = 0 of 9
Related peptides
Common questions
How long does PT-141 act in the body?
The half-life values we found are approximately 2.7 hours (range 1.9-4.0 h) (subcutaneous); mean t1/2 1.85 to 2.09 h (intranasal). A half-life is how long the amount in the body takes to fall by half; it is not the same as how long an effect lasts.
How does PT-141 work?
It is a melanocortin receptor agonist; the label says the way it improves low desire in women is unknown.[1]
Does PT-141 act on the brain?
The cached papers describe receptor agonism but do not measure brain activity, so a brain mechanism is not established here.
Calculated from abstracts with brain imaging or cns measure 0; abstracts checked 9. Formula: CNS-mechanism measurements found = 0 of 9
More on PT-141
Sources
- 1These highlights do not include all the information needed to use VYLEESI ® safely and effectively. See full prescribing information for VYLEESI VYLEESI (bremelanotide injection), for subcutaneous use Initial U.S. Approval: 2019FDA label (Vyleesi), DailyMed · current labeldailymed.nlm.nih.govAccessed 2 Oct 2026
- 2Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction.International journal of impotence research · 2004PMID 14963471Accessed 2 Oct 2026
- 3An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist.The journal of sexual medicine · 2006PMID 16839319Accessed 2 Oct 2026
- 4Usefulness of ambulatory blood pressure monitoring to assess the melanocortin receptor agonist bremelanotide.Journal of hypertension · 2017PMID 27977473Accessed 2 Oct 2026
- 5Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra.International journal of impotence research · 2004PMID 14999221Accessed 2 Oct 2026
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