# PT-141 Dosage as Studied: The Label and Trial Regimens (Bremelanotide) > PT-141 dosage reported as a finding: the label specifies 1.75 mg subcutaneous as-needed, max 1/24 h and 8/month. Half-life ~2.7 h. Routes and durations from the trials. Not a protocol. Reported strictly as findings — the studied regimen, the half-life, the routes — never as a protocol for any reader to follow. ## Before the details This page reports the PT-141 dosage that appears in the FDA label and the clinical trials — and only as a record of what was studied. It is not instructions. In the approved use, the drug is a single as-needed injection just under the skin, taken before anticipated activity, with firm limits on how often. The peptide leaves the body fairly quickly (its half-life is under three hours), though the desire effect was measurable for longer in a brain-scan study. We state these numbers because they are documented facts about the drug; we do not recommend any dose for any individual, and the approved product is a prescription medicine. ## What is the PT-141 dosage? Reported as a label fact: the approved bremelanotide regimen is 1.75 mg subcutaneously, as needed, taken at least 45 minutes before anticipated sexual activity, with no more than one dose per 24 hours and no more than eight doses per month [6]. That frequency ceiling is tied to tolerability — chiefly nausea — and to the transient blood-pressure effect [6]. This is the studied and labeled regimen, not a protocol for a reader to follow. ## The dose studied in women (1.75 mg SC, as-needed) The PT-141 dosage for women is the one with Phase 3 evidence behind it. In premenopausal women with HSDD, the studied and approved dose is 1.75 mg subcutaneously, as needed, capped at one dose per 24 hours and eight per month [6]. That is the exact regimen used across the RECONNECT trials in which the coprimary desire and distress endpoints were met [3]. Earlier Phase 2 dose-finding work evaluated 0.75, 1.25, and 1.75 mg subcutaneous before 1.75 mg was carried forward [6]. Reported as label and trial facts, not as guidance for any person. ## How much PT-141 was studied? The literature describes doses, not personal recommendations. The Phase 3 trials and the label used 1.75 mg subcutaneous as-needed [3][6]; Phase 2 dose-finding spanned 0.75-1.75 mg [6]; early intranasal research in men used much higher milligram doses (dose-escalation to roughly 7-20 mg, with statistically significant erectile response above 7 mg) before that route was discontinued [1]; and a Phase 1 obesity research protocol used subcutaneous doses up to 2.5 mg as often as three times daily for 15 days [7]. We report what was studied in each context and recommend no dose for anyone. ## How much PT-141 to inject (as studied) In the approved use and the pivotal trials, the studied subcutaneous amount was 1.75 mg per as-needed use [3][6]. The much larger milligram figures that appear in older literature belong to the early intranasal program in men, which used a different route and was later discontinued for pharmacokinetic variability [1]. The two should not be conflated. As above, these are documented study and label figures, not instructions. ## The approved bremelanotide dose The approved bremelanotide dose is 1.75 mg subcutaneous, as needed, at least 45 minutes before anticipated sexual activity, capped at one dose per 24 hours and eight per month, per the US prescribing information [6]. The approved product is a prefilled autoinjector; it does not require reconstitution [6]. "PT-141 research chemical" sold as a lyophilized powder is a laboratory material, not the finished drug product, and this site provides no preparation or self-administration instructions for it. ## How PT-141 is administered The approved route is a subcutaneous injection into the abdomen or thigh, taken on an as-needed basis before anticipated activity [6]. Earlier development used an intranasal formulation, and early pharmacology also used intravenous dosing; the intranasal route was discontinued because of pharmacokinetic variability [1][6]. The cyclic lactam structure of the peptide confers more stability than linear melanocortin peptides, which is part of why the subcutaneous product behaves predictably [6]. ## Reconstitution in the research context The approved product is a prefilled autoinjector and does not require reconstitution [6]. Lyophilized "PT-141 research chemical" is a laboratory material, not the finished drug, and exists outside the pharmaceutical approval framework with no regulatory oversight of its identity, purity, or concentration. This site does not provide preparation, reconstitution, or self-administration instructions — it summarizes the published record only. ## Dosing frequency on the label The label limits use to no more than one 1.75 mg dose per 24 hours and no more than eight doses per month [6]. Tolerability — especially nausea, which drove most discontinuations in the long-term extension — and the transient blood-pressure effect inform that ceiling [4][6]. Reported as a label fact, not as a schedule for any reader. ## How long PT-141 lasts (half-life and timing) How long does PT-141 last? After subcutaneous dosing, the terminal half-life is about 2.7 hours (range 1.9-4.0 h) per the US label, with a median Tmax (time to peak concentration) near 0.5-1.0 hour [6]. Early intranasal studies reported a similar half-life of 1.85-2.09 h [1]. The pharmacologic clearance is quick — but the measured desire effect outlasts the drug in plasma: in the functional-MRI study, the increase in sexual desire was detectable for up to 24 hours after a single dose [5]. So "how long it lasts" has two answers: the molecule clears in a few hours, while the central effect was measurable for up to a day. ## PT-141 half-life The PT-141 half-life is approximately 2.7 hours (range 1.9-4.0 h) after subcutaneous administration, per the US prescribing information [6]. 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 excretion 64.8% renal and 22.8% fecal from a radiolabeled dose [6]. Early intranasal work reported a comparable half-life of 1.85-2.09 h [1]. --- A chrome-bright console reading of the bremelanotide record — the one approved indication, the modest effect, and the honest tolerability profile logged to source, with the community field reports quarantined apart; not a clinic, not a vendor, not a prescription.