DOSING LITERATURE / LABEL & TRIALS
PT-141 dosage, half-life, and onset — strictly as the trials and label report them.
The approved label dose, the Phase 2 dose-finding range, the pharmacokinetics, and the onset window. Reported as findings, never as a protocol for anyone to follow.
Before the numbers
This page reports PT-141 dosage the way the studies and the official label state it — and that is all. Nothing here tells any reader what to take. The approved drug is given as a 1.75 mg shot under the skin, used only when needed, well before sex. It starts working in roughly half an hour to forty-five minutes and clears the body fast (about a 2.7-hour half-life). Powder sold as "research chemical" is laboratory material, not the approved product, and this page gives no preparation instructions for human use. Read it as a record, not a guide.
PT-141 dosage in the research literature
The PT-141 dosage that carries the evidence is the approved one. The US prescribing information specifies 1.75 mg subcutaneously (injected just under the skin), 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]. Subcutaneous (SC) is the only approved route; the early intranasal route was discontinued for pharmacokinetic variability [6][7].
That single figure — 1.75 mg SC as-needed — is what the two RECONNECT Phase 3 trials administered and what the 52-week extension carried forward [3][4]. It is reported here as a label and trial finding, not as guidance to any individual.
Doses studied in trials
Before settling on 1.75 mg, the program ran dose-finding. Phase 2 subcutaneous dose-finding in women tested 0.75, 1.25, and 1.75 mg, and 1.75 mg became the dose carried into Phase 3 [3]. The early intranasal work in men escalated to roughly 7-20 mg, with a statistically significant erectile response above 7 mg [7]. Separately, Phase 1 obesity research used subcutaneous doses up to 2.5 mg as often as three times daily for 15 days — a research protocol, not a sexual-function regimen [6]. These are the doses the literature studied; none is a recommendation.
The common question "how much PT-141 to inject" has only a label answer (1.75 mg SC, as-needed) and a set of trial doses above — both stated as findings.
How long PT-141 lasts
How long PT-141 lasts is a pharmacokinetics question with documented answers. After subcutaneous injection, onset is fast — median Tmax is about 0.5-1.0 h, and erectile-response onset in the early male studies was around 30 minutes [6][7]. The label instructs dosing at least 45 minutes before activity, which frames the practical onset window [6]. The drug then clears quickly rather than lingering, which is why it is an as-needed product, not a daily one [6].
PT-141 half-life
PT-141 half-life is short. The US prescribing information reports a terminal half-life of approximately 2.7 hours (range 1.9-4.0 h) after subcutaneous administration [6]. Early intranasal studies reported a comparable 1.85-2.09 h [7]. Supporting pharmacokinetics from the label: volume of distribution ~25.0 L, clearance ~6.5 L/hr, ~21% serum protein binding, metabolism by hydrolysis of the cyclic-peptide amide bonds and peptidase digestion, and excretion 64.8% renal and 22.8% fecal from a radiolabeled dose [6]. The cyclic lactam structure makes it more stable than linear melanocortin peptides, but it is still cleared on the order of hours, not days [6].
Routes studied, and a note on research material
Three routes appear in the record: subcutaneous (the approved route), intranasal (early development, discontinued for PK variability), and intravenous (early pharmacology) [6][7]. The approved bremelanotide product is supplied as a ready-to-use subcutaneous autoinjector — not reconstituted [6].
By contrast, lyophilized "PT-141 research chemical" powder is a non-approved laboratory material with no regulatory oversight of identity, purity, or concentration [6]. This site gives no reconstitution or preparation protocol for human use, and recommends no dose to anyone. The dosing figures above are a record of what was studied and what the label states — see the nausea and tolerability page for why the as-needed schedule and dose matter, and the cited references for sources.