Dosage · Section 05
PT-141 dosage as it appears in the trials and the approved label
Reported strictly as findings, never as a protocol: the label dose, the Phase 2 dose-finding range, the routes studied, and the pharmacokinetics.
Before the details
This page reports PT-141 dosage as it was studied and labeled — as findings, not as instructions. The short version: the approved bremelanotide label specifies 1.75 mg injected just under the skin (subcutaneous), used as needed, no more than once in 24 hours and no more than 8 times a month [6]. The Phase 3 RECONNECT trials used that same 1.75 mg as-needed dose [3]. Earlier dose-finding tried 0.75, 1.25, and 1.75 mg. The drug clears quickly — a terminal half-life around 2.7 hours [6]. None of this is a recommendation for any reader; dosing is a prescriber's decision.
PT-141 dosage as studied in the trials and label
Reported as a finding: the US prescribing information specifies 1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated sexual activity, with no more than one dose per 24 hours and no more than 8 doses per month [6]. That is the approved regimen for the approved indication (premenopausal women with HSDD), and it is the dose the RECONNECT Phase 3 trials self-administered [3].
The dose-finding history adds context. Phase 2 subcutaneous dose-ranging in women evaluated 0.75, 1.25, and 1.75 mg before the 1.75 mg dose was carried into Phase 3 [3]. Early intranasal research in men, by contrast, escalated to roughly 7-20 mg, with a statistically significant erectile response above 7 mg [1] — a different route, a different population, and an investigational context. A Phase 1 metabolic protocol dosed subcutaneously up to 2.5 mg up to three times daily for 15 days; that was a research protocol, not a therapeutic regimen, and the high-frequency dosing is where weight and appetite effects appear [6]. We report every one of these as a measured datum, not as a number to copy.
PT-141 half-life and how long it lasts
The PT-141 half-life is short. The approved label reports a terminal half-life of approximately 2.7 hours (range 1.9-4.0 h) after subcutaneous dosing, with a median time-to-peak (Tmax) of about 0.5-1.0 hours [6]. Early intranasal studies reported a similar half-life, roughly 1.85-2.09 hours [1]. In plain terms: the molecule reaches its peak within an hour and is largely cleared within a working day, which is consistent with its as-needed, before-activity dosing design rather than a daily-maintenance one. "How long does PT-141 last" maps onto that pharmacokinetic window — peak fast, gone fast.
Routes studied and pharmacokinetics
Three routes appear in the record. Subcutaneous is the approved route and the one carried through Phase 3 [6]. Intranasal was the early-development route in men and was discontinued for pharmacokinetic variability [1]. Intravenous appeared in early pharmacology [1]. The cyclic lactam ring gives the molecule more stability than the linear melanocortin peptides it descends from.
The pharmacokinetics, from the label: volume of distribution about 25.0 L, clearance about 6.5 L/hr, roughly 21% serum protein binding, metabolism by hydrolysis of the cyclic-peptide bonds and peptidase digestion, and excretion split 64.8% renal and 22.8% fecal in a radiolabeled-dose study [6]. These are the numbers behind the half-life and the dosing window.
On reconstitution and "research chemical" material
The approved product is a pre-filled, single-dose subcutaneous autoinjector — so for the approved drug there is no reconstitution step at all [6]. Lyophilized (freeze-dried) material sold as a "PT-141 research chemical" is a different, unapproved form, with no regulatory oversight of its identity, purity, or concentration, and this site offers no preparation or dosing protocol for it. We draw that line clearly: the cited dosing record describes the approved finished drug and the trial protocols; it is not a guide for preparing unapproved material, and it is not a recommendation for any individual to follow.