PT-141 dosage in the research and the label

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This page reports PT-141 dosage as it appears in the trials and the FDA label, and nothing more. It prescribes no dose for any reader. The one approved dose — for low sexual desire causing distress in premenopausal women — is 1.75 mg injected just under the skin, taken only as needed, with hard limits of one dose per 24 hours and no more than eight per month. The drug clears the body fast: its terminal half-life is about 2.7 hours. Everything here is a regulatory or trial finding, cited to source. Material sold as a 'research chemical' is for laboratory use only.

PT-141 dosage as studied in the trials and label

The PT-141 dosage in the approved label is 1.75 mg subcutaneous, as needed, taken at least 45 minutes before anticipated sexual activity, with no more than one dose per 24 hours and no more than 8 doses per month ^[6]. That regimen is reported here strictly as the label finding for the approved HSDD indication in premenopausal women — not as guidance for anyone to follow.

The dose was chosen through dose-finding. Phase 2 subcutaneous studies in women tested 0.75 mg, 1.25 mg, and 1.75 mg, and the 1.75 mg dose carried into the pivotal RECONNECT trials ^[3]. Earlier intranasal research in men with erectile dysfunction escalated to roughly 7-20 mg, with a statistically significant erectile response above 7 mg, but that route was discontinued for pharmacokinetic variability and never reached approval ^[1]. A Phase 1 obesity research protocol in women used subcutaneous doses up to 2.5 mg, up to three times daily for 15 days — a research protocol only, and the basis for the appetite/weight observations tied to MC4R's role in hunger circuits.

PT-141 dosage for women in the approved indication

For the approved indication — acquired, generalized HSDD in premenopausal women — the labeled dose is 1.75 mg subcutaneous, as needed, at least 45 minutes before anticipated sexual activity, observing the one-per-24-hours and eight-per-month ceilings ^[6]. This is the only population and the only dose the FDA approval covers. It is reported here as the regulatory finding; this digest recommends no dose for any individual, and any use outside the approved indication is off-label and outside the approval.

PT-141 half-life and pharmacokinetics

The terminal half-life of bremelanotide is approximately 2.7 hours (range 1.9-4.0 h) after subcutaneous administration, per the US prescribing information; early intranasal studies reported 1.85-2.09 h ^[6]. Median Tmax — the time to peak concentration — is about 0.5-1.0 h after a subcutaneous injection ^[6]. Volume of distribution is roughly 25.0 L, clearance about 6.5 L/hr, and serum protein binding around 21% ^[6]. It is metabolized by hydrolysis of the cyclic-peptide amide bonds and by peptidase digestion, and excreted 64.8% renally and 22.8% fecally (radiolabeled dose) ^[6]. The cyclic lactam structure gives it more stability than a linear melanocortin peptide ^[1].

How long does PT-141 last?

Two different clocks answer this. The drug itself clears quickly: a short terminal half-life of about 2.7 hours means most of the compound is gone within a day ^[6]. The effect, however, can outlast the molecule — the crossover fMRI study observed increased sexual desire for up to 24 hours after a single dose ^[5]. That gap between drug clearance and effect duration is consistent with a central, downstream mechanism: the receptor signal sets something in motion that persists after the peptide is metabolized.