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PT-141 Half-Life: How Long It Stays in Your System

How long PT-141 stays in the body, how that shapes dosing frequency, and what is known about drug testing.

Medically reviewed by Juan Pablo Frías, MD · · DisclosureMelanocortin agonistUpdated
Half-life
approximately 2.7 hours (range 1.9-4.0 h)
subcutaneous, in people · FDA label (Vyleesi)
Dosing interval
Varies by study
as used in studies
WADA
Not listed
2026 Prohibited List
Detection window
Not found
None reported as of 2 Oct 2026

PT-141 half-life

A half-life depends on the route (under the skin, into a vein, by mouth or nasal spray) and the species it was measured in, so we report each value with its route and source.

PT-141 half-life by route
RouteHalf-lifeMeasured inSource
subcutaneousapproximately 2.7 hours (range 1.9-4.0 h)PeopleFDA label (Vyleesi)
intranasalmean t1/2 1.85 to 2.09 hPeopleInternational journal of impotence research 2004, PMID 14963471
As labelledapproximately 2.7 hours (range 1.9-4.0 h), single subcutaneous dosePeopleFDA label (Vyleesi)

What half-life means

Half-life is the time it takes for the amount of a drug in the blood to fall by half. After one half-life, about 50% is left; after two, about 25%; after four to five, only a few percent remain.

  • A long half-life lets a drug be dosed less often, for example once a week.
  • A short half-life means levels rise and fall quickly, which is why some peptides are given daily or more often.
  • Effects can outlast blood levels, so half-life alone does not tell you how long a drug works.

What it means for dosing frequency

Dosing intervals used in published studies of PT-141:

Changing the interval changes how much drug builds up between doses, so it is not a free choice.

Drug tests and sport

Not on the WADA Prohibited List

PT-141 (bremelanotide) is not named on the list and is FDA-approved (Vyleesi), so S0 does not apply. It does not fit the named S2 subclasses.

Anti-doping labs use tests built for specific substances. Whether a given test detects PT-141, and for how long, is not reported in the anti-doping literature we checked (as of 2 Oct 2026).

Common questions

How long does PT-141 stay in your system?

Its reported half-life is approximately 2.7 hours (range 1.9-4.0 h) (subcutaneous); mean t1/2 1.85 to 2.09 h (intranasal). Most of a dose is gone after about four to five half-lives.

What is the half-life of PT-141?

Approximately 2.7 hours (range 1.9-4.0 h) (subcutaneous); mean t1/2 1.85 to 2.09 h (intranasal), from the sources cited below.

Is PT-141 on the WADA prohibited list?

No, it is not listed. PT-141 (bremelanotide) is not named on the list and is FDA-approved (Vyleesi), so S0 does not apply. It does not fit the named S2 subclasses.

More on PT-141

DosageDoses used in published studies, with the source for each.CalculatorVial, water and dose to syringe units.Side effectsWhat labels and studies report, and what is unknown.ResultsStudy outcomes and when they were measured.PricePrice per mg and per week from dated listings. No vendor links.Legal statusFDA, compounding and WADA status with dates.

Sources

  1. 1World Anti-Doping Code International Standard Prohibited List 2026World Anti-Doping Agency · 2026wada-ama.orgAccessed 2 Oct 2026
  2. 2These 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
  3. 3Double-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
  4. 4Prespecified and Integrated Subgroup Analyses from the RECONNECT Phase 3 Studies of Bremelanotide.Journal of women's health (2002) · 2022PMID 35230162Accessed 2 Oct 2026
  5. 5Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials.Obstetrics and gynecology · 2019PMID 31599840Accessed 2 Oct 2026
  6. 6Phase I Randomized Placebo-controlled, Double-blind Study of the Safety and Tolerability of Bremelanotide Coadministered With Ethanol in Healthy Male and Female Participants.Clinical therapeutics · 2017PMID 28189361Accessed 2 Oct 2026
  7. 7Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial.Women's health (London, England) · 2016PMID 27181790Accessed 2 Oct 2026

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