# PT-141 Dosage: The Approved Label, Half-Life, and Pharmacokinetics | PT-141 > PT-141 dosage reported as findings only: the approved bremelanotide label is 1.75 mg subcutaneous as needed. Half-life ~2.7 h, onset, and pharmacokinetics from the prescribing information. The approved regimen, the half-life, and the pharmacology — as study and label findings, never as instructions. ## Before the numbers A quick, important framing first. Everything on this page is reported as a *finding* — what the approved label states and what the trials used — and nothing here is a recommendation for any individual to follow. This is a reading desk, not a prescriber. With that said: the approved PT-141 dosage for the one approved group is a single 1.75 mg dose under the skin, taken only as needed, with firm ceilings on how often. The drug clears the body fast, with a half-life of a few hours. We'll walk through each figure and where it comes from. ## What is the PT-141 dosage in the approved label? Reported as the regulatory finding, not as advice: the U.S. prescribing information specifies bremelanotide **1.75 mg subcutaneously** (injected just under the skin), **as needed**, at least 45 minutes before anticipated sexual activity, for HSDD in premenopausal women [6]. The label sets hard limits — **no more than one dose per 24 hours** and **no more than 8 doses per month** [6]. Those limits matter as much as the dose. They define the entire approved pattern of use, and they sit far below the high-frequency schedules used in unrelated research (like the appetite studies). The approved finished product is a prefilled single-use autoinjector — it isn't mixed or measured by the user [6]. Material sold as a "PT-141 research chemical" is a different thing entirely, a laboratory reagent outside this framework, and this digest gives no preparation or self-administration steps for it [6]. See the full [PT-141 dosage in the research literature](/dosage) summarized in the table below. ## PT-141 Dosage for Women in the Approved Label The approved PT-141 dosage for women — specifically premenopausal women with acquired, generalized HSDD — is the one the label authorizes: **1.75 mg subcutaneously, as needed**, with a maximum of one dose per 24 hours and no more than 8 per month [6]. Before approval, Phase 2 dose-finding in women had compared 0.75, 1.25, and 1.75 mg, and the 1.75 mg dose carried forward into the pivotal RECONNECT trials [3]. We report this as the regulatory and trial finding, full stop — not as guidance, and not extended to any group the approval doesn't cover. There is no approved PT-141 dosage for men or for postmenopausal women, because there is no approval for those uses [6]. ## How Long PT-141 Lasts: Half-Life and Onset How long PT-141 lasts comes straight from the pharmacokinetics. After a subcutaneous dose, the prescribing information reports a **terminal half-life of about 2.7 hours** (range 1.9–4.0 h) — the time for the blood level to fall by half [6]. It reaches the bloodstream quickly, with a median time to peak (**Tmax**) around 0.5–1.0 hour [6]. That fast on, fast off profile is why the approved use is "as needed before activity" rather than a daily pill — and it's part of why the label asks for the dose at least 45 minutes ahead [6]. The early intranasal formulation reported a comparable half-life of roughly 1.85–2.09 hours before that route was discontinued for variable absorption [6]. ## PT-141 Half-Life in the Prescribing Information To put the PT-141 half-life beside the rest of its pharmacology: terminal half-life **~2.7 hours** (range 1.9–4.0 h), volume of distribution about 25.0 L, and clearance about 6.5 L/hr, all from the U.S. prescribing information [6]. Roughly 21% of the drug is bound to serum proteins [6]. It's broken down by hydrolysis of its cyclic-peptide bonds and ordinary peptidase digestion, then excreted mostly by the kidneys (about 64.8%) with the remainder in feces (about 22.8%) in a radiolabeled study [6]. These are reported as pharmacokinetic findings from the label — useful for understanding the drug, not a basis for any dosing decision. ## What the trials and label used, at a glance Pulled together as findings only, here is the dosing landscape across PT-141's development [3] [6] [7]: - **Approved (HSDD, women):** 1.75 mg subcutaneously, as needed, at least 45 minutes before activity; max one dose / 24 h and 8 / month [6]. - **Phase 2 dose-finding (women):** 0.75, 1.25, and 1.75 mg subcutaneously [3]. - **Early intranasal research (men, ED):** dose-escalation to roughly 7–20 mg; significant erectile response above ~7 mg [1]. - **Phase 1 appetite research (women):** subcutaneous up to 2.5 mg, up to three times daily for 15 days — a research protocol only, not an approved pattern [7]. Every row is a study or label figure. None is a protocol for a reader to follow. For the tolerability that goes with these figures, read [PT-141 side effects](/side-effects). --- A friendly, plain-English guide to the PT-141 (bremelanotide) research — the one approved use, the modest benefit, and the nausea-led tolerability cost read first and cited to source, with community field reports kept gently to one side and clearly marked unverified; a reading desk, not a shop, and nothing here dosed, sourced, or sold.