# PT-141 Dosage in the Research and Label Record | Bremelanotide

> PT-141 dosage as reported, not recommended: the approved label is 1.75 mg subcutaneous as-needed, max 1 dose per 24 h and 8 per month. Half-life ~2.7 h. Trial and label figures only.

What the approved label specifies, what the dose-finding trials tested, and how long the drug lasts. These are figures of record. They are not instructions for any reader to follow.

## The short version

This page reports the PT-141 dosage figures that appear in the trials and on the approved label — and nothing here is a recommendation. In its approved use, the label specifies bremelanotide 1.75 mg injected under the skin (*subcutaneous* — just under the skin), taken only as needed, with hard limits: no more than one dose in 24 hours and no more than eight in a month [11]. The drug clears quickly: its half-life — the time for the amount in the blood to fall by half — is about 2.7 hours [11]. We state these as facts on record because people search for them; we do not tell anyone to use them.

## PT-141 Dosage in the Research Literature

Reported strictly as findings: the approved label specifies bremelanotide **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]. This is the figure of record for the approved premenopausal-HSDD indication — not a protocol for any individual to follow.

The dose was established through dose-finding work. A Phase 2 randomized, placebo-controlled study evaluated subcutaneous bremelanotide at 0.75, 1.25, and 1.75 mg in premenopausal women with female sexual dysfunction, which supported advancing the 1.75 mg dose into Phase 3 [8]. Early development also explored other routes and higher figures: intranasal dose-escalation in men reached roughly 7-20 mg, and a Phase 1 obesity protocol administered subcutaneous doses up to 2.5 mg, up to three times daily for 15 days — a research protocol only, and not an approved or recommended regimen [1]. The approved route is subcutaneous; the intranasal route was discontinued in development due to pharmacokinetic variability.

## How long PT-141 lasts (half-life and timing)

After a subcutaneous dose, bremelanotide reaches peak blood concentration quickly — a median time to maximum (Tmax) of about 0.5 to 1.0 hours — and is then cleared with a terminal half-life of approximately 2.7 hours (range 1.9-4.0 hours) per the prescribing information [11]. Early intranasal studies reported a comparable half-life of 1.85-2.09 hours.

In practical pharmacology terms, that is a short-acting, fast-on profile — which is why the approved use is *as needed*, taken ahead of anticipated activity rather than dosed continuously [11]. The supporting parameters: a volume of distribution of about 25.0 L, clearance of about 6.5 L/hr, roughly 21% serum protein binding, and metabolism by hydrolysis of the cyclic-peptide amide bonds and by peptidase digestion [11].

## PT-141 half-life

The terminal **PT-141 half-life** is approximately 2.7 hours after subcutaneous administration, with a labeled range of 1.9 to 4.0 hours [11]. The molecule's cyclic lactam structure confers greater stability than the linear melanocortin peptides it is related to, but it is still a short-acting agent — its effect on desire in the fMRI study persisted for up to 24 hours even though the drug itself is cleared within hours, a reminder that a downstream behavioural effect can outlast the molecule's presence in blood [5][11].

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A broadsheet reading of the PT-141 (bremelanotide) record — the one approved indication set in banner type, the modest measured effect printed beside the re-analysis that contests it, the nausea-led tolerability cost run in full, and the unverified field reports kept on their own torn dispatch; no clinic behind the masthead and nothing here dosed, dispensed, or sold.