# PT-141 Dosage: Label & Pharmacokinetics (Bremelanotide)

> PT-141 (bremelanotide) dosage in research context: the 1.75 mg approved label dose, terminal half-life ~2.7 h, Tmax, and the routes studied — documented from the FDA label, no individual advice.

The approved label dose, the half-life, and the routes studied — as documented in the US prescribing information and trial literature, never as a recommendation.

## The short version

This page describes the **PT-141 dosage** as it appears in the FDA label and the trial record — it is not advice for any person. The approved drug, bremelanotide, has a single labeled dose for its single approved use: 1.75 mg injected under the skin, taken as needed at least 45 minutes before anticipated activity, with a ceiling of one dose in 24 hours and no more than eight doses per month [7].

The drug clears fairly quickly. Its **half-life** (the time for half the dose to leave the blood) is about 2.7 hours [7]. It reaches peak blood levels roughly half an hour to an hour after injection [7]. Everything below is documented pharmacology, presented in third person, with no instruction to take any amount.

## PT-141 dosage: the approved label figures

The US prescribing information specifies bremelanotide 1.75 mg administered subcutaneously, as needed, for acquired generalized HSDD in premenopausal women [7]. The label sets explicit limits: no more than one dose per 24 hours and no more than eight doses per month [7]. These are documented label parameters for the approved indication, not a protocol recommended for any individual.

Research doses outside that label exist in the development record. Phase 2 subcutaneous dose-finding in women studied 0.75, 1.25, and 1.75 mg [3]. Early intranasal research in men escalated to roughly 7–20 mg, with a statistically significant erectile response above 7 mg, but that route was discontinued due to pharmacokinetic variability [1]. None of these is an approved or recommended dose.

## PT-141 dosage for women: the on-label context

The only **PT-141 dosage for women** that is FDA-approved is the 1.75 mg subcutaneous as-needed regimen for premenopausal women with HSDD, with the one-per-24-hours and eight-per-month ceilings [7]. That regimen is the one tested in the RECONNECT Phase 3 trials, where 1.75 mg produced the measured improvements in desire and distress [3].

The approval is specific to premenopausal women; it does not extend to postmenopausal women, for whom the label dose has not been established [9]. Preclinically, female-rat work showed that PT-141 selectively increased appetitive (solicitational) sexual behavior without affecting reflexive behaviors or general activity, which is the mechanistic basis for studying it in women in the first place [2].

## How long does PT-141 last

The pharmacokinetics answer **how long does PT-141 last** in the body precisely. After subcutaneous injection, bremelanotide has a terminal half-life of approximately 2.7 hours, with a range of 1.9–4.0 hours per the prescribing information [7]. Median time to peak concentration (Tmax) is about 0.5–1.0 hours [7]. Early intranasal studies reported a slightly shorter half-life of 1.85–2.09 hours [1].

The rest of the PK profile is well characterized: volume of distribution about 25.0 L, clearance about 6.5 L/hr, roughly 21% serum protein binding, with metabolism by hydrolysis of the cyclic-peptide bonds and excretion split 64.8% renal and 22.8% fecal [7]. The cyclic lactam structure is what gives it greater stability than linear melanocortin peptides [1].

## Routes studied and the research-chemical caveat

Three routes appear in the development record. Subcutaneous is the approved route [7]. Intranasal was used in early development but discontinued because of variable pharmacokinetics [1]. Intravenous was used in early pharmacology work [1].

A caution belongs here. Material sold as a "PT-141 research chemical" sits outside the pharmaceutical approval framework — there is no regulatory oversight of its identity, purity, or concentration, so the label figures above cannot be assumed to apply to it [7]. This page documents the approved drug's pharmacology and recommends no dose, route, or regimen to any individual.

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An azure-ruled ledger of the PT-141 (bremelanotide) record — the 2019 approval, the 1,267-woman trials, and the half-life on the label entered as cited credits, with the small-effect critique, the ~40% nausea, and the premenopausal-HSDD-only boundary ruled in plain sight as the debits they are; no clinic balances behind this page and nothing here is dosed, prescribed, or sold.