Doses studied
PT-141 dosage: what the label specifies and what the studies tested
The approved label dose, the pharmacokinetics, and the doses used in research — described, not prescribed.
The gist
This page reads the PT-141 dosage record as it is written down — in the approved drug label and in the published studies — and recommends nothing to any individual. For the approved use (HSDD in premenopausal women), the US prescribing information specifies one dose: 1.75 mg injected under the skin as needed, no more than one dose in 24 hours and no more than eight doses a month [7]. The drug clears the body fairly quickly: its terminal half-life (the time for blood levels to fall by half once elimination dominates) is about 2.7 hours [7]. Research has tested other doses and routes — intranasal and intravenous in early work, higher doses in male and metabolic studies — but those are study protocols, not guidance [1][7]. We describe what was given, to whom, by which route. We never tell a reader to take anything.
PT-141 dosage: the approved label
The authoritative PT-141 dosage figure is the labeled one. The US prescribing information for bremelanotide injection specifies 1.75 mg subcutaneously, as needed, taken at least 45 minutes before anticipated sexual activity, with a ceiling of one dose per 24 hours and no more than eight doses per month [7]. That label also carries a warning about a transient blood-pressure increase and contraindicates use in uncontrolled hypertension or known cardiovascular disease [7]. These are documented as the labeled dose and labeled warnings — not as a recommendation to any reader.
PT-141 dosage for women
The PT-141 dosage for women that a regulator has reviewed is the HSDD label dose: 1.75 mg subcutaneously as needed, within the monthly ceiling above [7]. Before approval, Phase 2 dose-finding in women tested 0.75, 1.25, and 1.75 mg subcutaneously [7]. Separately, a Phase 1 metabolic research protocol gave women up to 2.5 mg subcutaneously up to three times daily for 15 days [7] — that was a research protocol studying caloric intake and body weight, not an approved or recommended regimen, and it is unrelated to the desire indication.
PT-141 injection: route and reconstitution context
The approved PT-141 injection is subcutaneous — under the skin [7]. The approved product is a prefilled pharmaceutical, so reconstitution does not apply to it; "how to reconstitute" questions arise around the unregulated research-chemical form, which sits outside the approval framework with no oversight of identity, purity, or concentration [7]. We do not provide reconstitution or self-administration instructions. Other routes appear only in early research: intranasal dosing was explored in development but discontinued due to pharmacokinetic variability, and intravenous dosing was used in early pharmacology [7].
How long does PT-141 last
On the question of how long does PT-141 last in the body, the label is precise: after subcutaneous injection the terminal half-life is approximately 2.7 hours (range 1.9–4.0 hours), and peak blood levels arrive around 0.5–1.0 hours after the dose [7]. Early intranasal studies reported a slightly shorter half-life of 1.85–2.09 hours [7]. The desire effect itself can outlast the drug in blood: the brain-imaging study found increased sexual desire for up to 24 hours after a single dose [5].
Pharmacokinetics in detail
The label documents the rest of the pharmacokinetic profile: a volume of distribution of about 25.0 L, clearance near 6.5 L/hr, roughly 21% serum protein binding, metabolism by hydrolysis of the cyclic-peptide amide bonds plus peptidase digestion, and excretion that is 64.8% renal and 22.8% fecal from a radiolabeled dose [7]. The NIH LiverTox monograph adds that the drug is metabolized by amide-bond hydrolysis and has minimal drug-drug interactions [10]. These figures describe how the approved drug behaves; they are not a basis for any individual dosing decision.