# PT-141 Dosage in the Research and Label Record (Bremelanotide) > PT-141 dosage as documented: the approved bremelanotide label dose (1.75 mg SC, as needed), the trial dose-ranging, half-life (~2.7 h), and pharmacokinetics. Reported as findings, not a protocol. The approved dose, the dose-ranging history, the half-life, and the pharmacokinetics — reported as published findings, never as a protocol for any reader to follow. ## Before the details This page reports PT-141 dosage the way a label and a set of trials record it — as documented numbers, not as instructions. The approved medicine has a single labeled dose for its single approved use, and the research literature records the doses that were tested along the way. Nothing here tells anyone what to take. "Subcutaneous" means injected just under the skin; a "half-life" is how long the body takes to clear half of a dose. Where a figure appears below, it is the figure a study or the FDA label published. Read it as a finding. It is not a recommendation, and it is not medical advice. ## PT-141 dosage in the research literature The approved dose is precise because a regulator set it. The US prescribing information for bremelanotide injection 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 eight doses per month** [11]. That is the labeled dose for the approved HSDD indication in premenopausal women, stated here as a label finding and not as a protocol. The path to that number is visible in the trial record. Phase 2 subcutaneous dose-finding in women evaluated 0.75 mg, 1.25 mg, and 1.75 mg before the 1.75 mg dose carried forward into the pivotal RECONNECT trials [3]. The early, off-label male erectile-dysfunction research used a different route entirely — intranasal dose-escalation reaching roughly 7-20 mg, with a statistically significant erectile response above 7 mg — and a Phase 1 obesity protocol in women administered subcutaneous doses up to 2.5 mg, up to three times daily for 15 days [1]. Those higher and more frequent regimens are research protocols, not approved uses, and the high-frequency dosing is precisely the context in which the appetite, blood-pressure, and pigmentation effects become most relevant. The route history matters too. Subcutaneous is the approved route; the intranasal route was explored early and discontinued because of pharmacokinetic variability, and intravenous administration appeared only in early pharmacology [11]. ## PT-141 dosage for women in the trials The question of PT-141 dosage for women has a single documented answer in the approved setting: **1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated sexual activity, no more than once per 24 hours and no more than eight times per month** [11]. This is the label's specification for premenopausal women with acquired, generalized HSDD, and it is reported here as the label finding, not as a course of action for any individual. The dose was not arbitrary. It is the dose carried from Phase 2 dose-ranging (0.75, 1.25, 1.75 mg) into both RECONNECT trials and the 52-week open-label extension, where it produced the integrated FSFI-desire (+0.35) and FSDS-DAO item-13 (-0.33) effects and the documented adverse-event profile [3] [4]. The cap on frequency is not incidental: it reflects the compound's pharmacology, where higher-frequency dosing is where the cardiovascular and pigmentation considerations concentrate [11]. ## How long does PT-141 last? After subcutaneous injection, bremelanotide reaches peak concentration quickly — a median Tmax (time to peak concentration) of roughly 0.5 to 1.0 hours — and the labeled timing of at least 45 minutes before activity reflects that onset [11]. It does not linger long. The terminal half-life is approximately 2.7 hours (range 1.9-4.0 hours) per the US prescribing information [11]; early intranasal studies reported a similar 1.85-2.09 hours [1]. The pharmacodynamic effect, though, outlasts the plasma curve. The fMRI study found increased sexual desire for up to 24 hours after a single dose, far longer than the few-hour half-life would suggest — a reminder that a drug's measurable duration of effect and its time in the bloodstream are not the same number [5]. ## PT-141 half-life and pharmacokinetics The PT-141 half-life is short and well-characterized. The terminal half-life is approximately 2.7 hours (range 1.9-4.0 hours) after subcutaneous administration [11]. The supporting pharmacokinetics, from the label: a volume of distribution of about 25.0 L, clearance of about 6.5 L/hr, roughly 21% serum protein binding, and elimination split 64.8% renal and 22.8% fecal in a radiolabeled-dose study [11]. Metabolism proceeds by hydrolysis of the cyclic-peptide amide bonds and ordinary peptidase digestion [11]. The cyclic lactam structure is the reason these numbers exist at all: the ring confers greater stability than a linear melanocortin peptide, which is what made a subcutaneous injectable feasible where linear analogues struggled [1]. For the receptor pharmacology behind the dose, see [how PT-141 works](/research); for the events that scale with frequency of dosing, see [PT-141 side effects](/side-effects). --- An after-dark poster reading of the bremelanotide record — the one approved use staged apart from the off-label male research, the modest endpoints set beside the numbers that qualify them, the nausea-led tolerability cost read in full, and the field reports pinned plainly to one side as unverified; no clinic behind the wall, and nothing here dosed, dispensed, or sold.