# PT-141 Dosage: The Label and Research-Dose Record | PT-141

> PT-141 dosage as documented: the FDA-labeled 1.75 mg as-needed dose, the pharmacokinetics and half-life, and the research-dose context — third person, no recommendation.

The FDA-labeled dose, the pharmacokinetics, and the research-dose history — reported as documented, with no recommendation for any individual.

## The short version

When people ask about **PT-141 dosage**, the only authoritative number is the one on the FDA label, and it applies to one approved use. For premenopausal women with HSDD, the approved bremelanotide dose is 1.75 mg injected under the skin, as needed, at least 45 minutes before anticipated activity — no more than one dose in 24 hours and no more than eight a month [7].

That is a labeled dose for an approved indication, reported here as documentation, not as advice for anyone. The medicine clears the body fairly quickly: its half-life is about 2.7 hours [7]. Earlier research used other doses and routes — a nasal spray for men with ED, higher injected doses in obesity studies — but those were research protocols, not approved uses [8]. This page reports the dose record and the pharmacokinetics straight; it makes no recommendation and lists no protocol to follow.

## PT-141 dosage: the approved label figure

The US prescribing information specifies the PT-141 dosage for the approved HSDD indication: 1.75 mg subcutaneous, as needed, with a maximum of one dose per 24 hours and no more than eight doses per month [7]. The label also defines the pharmacokinetics behind that schedule — terminal half-life ~2.7 hours (range 1.9–4.0 h), volume of distribution ~25.0 L, clearance ~6.5 L/hr, ~21% serum protein binding, and excretion roughly 64.8% renal and 22.8% fecal [7].

This is presented as the labeled dose for the approved population, in the third person. It is not a recommendation, and it does not apply to off-label or research-chemical use.

## PT-141 dosage for women

The PT-141 dosage for women on the label is the 1.75 mg as-needed subcutaneous dose described above, and it applies specifically to premenopausal women with acquired, generalized HSDD [7][10]. The Phase 2 dose-finding work that preceded approval tested 0.75, 1.25, and 1.75 mg subcutaneously, which is how 1.75 mg was selected [the dose-research record]. Postmenopausal women are outside the approved population, so no labeled dose applies to them. As everywhere on this site, this is documentation of what was studied and approved, not guidance for any individual.

## Research doses and routes studied

Historically, PT-141 was studied at other doses and by other routes. Early intranasal research in men with ED escalated to roughly 7–20 mg, with a statistically significant erectile response above ~7 mg [8]; the intranasal route was later discontinued due to pharmacokinetic variability. A Phase 1 obesity research protocol administered subcutaneous doses up to 2.5 mg, up to three times daily for 15 days — a research protocol only, not an approved use [1]. Routes studied span subcutaneous (the approved route), intranasal (early, discontinued), and intravenous (early pharmacology). The cyclic lactam structure gives PT-141 greater stability than linear melanocortin peptides. None of these research doses is a recommendation; they are the historical record of what investigators administered.

## How long does PT-141 last

How long does PT-141 last? By the label pharmacokinetics, the terminal half-life is approximately 2.7 hours (range 1.9–4.0 h) after subcutaneous administration, with median Tmax around 0.5–1.0 hour [7]. Early intranasal studies reported a similar half-life of 1.85–2.09 h [8]. Note that pharmacokinetic half-life (how long the drug stays in the blood) is not the same as how long a subjective effect is reported to last — the human fMRI study, for instance, observed increased desire for up to 24 hours, well beyond the plasma half-life [5]. The dosing rule on the label — as needed, with the daily and monthly caps above — reflects that as-needed design [7].

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A spectrometer-style readout of the PT-141 (bremelanotide) record — every value logged to its source and marked in-spec or contested, the lone 2019 approval for premenopausal HSDD calibrated against every off-label and research-chemical use that sits outside its band; no clinic behind the instrument and nothing here prescribed, dosed, or sold.