PT-141 dosage in the research and label record

Before the details

This page reports PT-141 dosage the way the studies and the FDA label state it — as a record, never as instructions for you to follow. The approved regimen for the one approved use is 1.75 mg injected just under the skin (subcutaneous), taken only when needed, with hard caps: no more than one dose in 24 hours and no more than eight a month ^[6]. The drug clears the body fairly fast, with a half-life of roughly 2.7 hours ^[6]. Material sold as a "PT-141 research chemical" is for laboratory use only and is not the approved product ^[6]. Nothing here is a dosing recommendation.

PT-141 dosage in the research and label record

The PT-141 dosage that anchors the entire record is the approved one: 1.75 mg subcutaneously, as needed, taken at least 45 minutes before anticipated sexual activity, with a ceiling of one dose per 24 hours and no more than eight doses per month ^[6]. That regimen is what the two RECONNECT Phase 3 trials used and what the US prescribing information specifies ^[3][6].

The dose was not arbitrary. Phase 2 subcutaneous dose-finding in women evaluated 0.75, 1.25, and 1.75 mg before the 1.75 mg as-needed regimen was carried into Phase 3 ^[6]. In the much earlier off-label male erectile research, an intranasal route was dose-escalated into the roughly 7-20 mg range, with a statistically significant erectile response reported above 7 mg — but that route was discontinued for pharmacokinetic variability and never approved ^[1]. A separate Phase 1 obesity protocol administered subcutaneous doses up to 2.5 mg, up to three times daily for 15 days; that was a research protocol only, and the appetite-circuit effects it probed are a pharmacological consideration, not an indication ^[6]. These figures are stated as findings; this site gives no individual dosing recommendation.

PT-141 dosage for women (the approved HSDD regimen)

For the approved indication — acquired, generalized HSDD in premenopausal women — the label specifies 1.75 mg subcutaneously as needed, self-administered in the abdomen or thigh 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 ^[6]. The label notes that the timing can be adjusted based on individual response and tolerability, and that a patient who sees no benefit after about eight weeks should, with their prescriber, reconsider continuing ^[6]. The 52-week extension confirmed the as-needed pattern held up over a year without new safety signals ^[4]. This is the labeled regimen for a prescribed medication, reported here as a label finding — not a protocol for anyone to follow on their own.

How long does PT-141 last?

How long does PT-141 last? After a subcutaneous dose, the drug reaches peak blood levels quickly — median time-to-peak is about 0.5 to 1.0 hour — and then clears with a terminal half-life of roughly 2.7 hours (range 1.9-4.0 hours) per the US prescribing information ^[6]. "Half-life" is the time for blood levels to fall by half. Early intranasal studies reported a similar half-life of about 1.85-2.09 hours ^[1].

The pharmacological effect outlasts the blood levels: the 2022 fMRI study found increased sexual desire persisting for up to 24 hours after a single dose, well beyond the time the drug itself remained in circulation ^[5]. That gap is why the label frames dosing around "at least 45 minutes before" activity rather than a strict on-off window ^[6].

PT-141 half-life and pharmacokinetics

The PT-141 half-life and the rest of the pharmacokinetics are well characterized in the label. Terminal half-life is approximately 2.7 hours (range 1.9-4.0 hours) after subcutaneous administration ^[6]. Volume of distribution is about 25.0 L and clearance about 6.5 L/hr; serum protein binding is roughly 21% ^[6]. The molecule is broken down by hydrolysis of its cyclic-peptide amide bonds and by peptidase digestion, and a radiolabeled dose was excreted 64.8% renally and 22.8% in feces ^[6].

The NIH LiverTox monograph adds the hepatic picture: as a parenterally administered melanocortin receptor agonist, bremelanotide is associated with mild serum-enzyme elevations and rare instances of clinically apparent acute liver injury, with metabolism by amide-bond hydrolysis and minimal drug-drug interactions ^[6]. The cyclic lactam structure is what gives PT-141 greater stability than linear melanocortin peptides — the chemistry behind its usable pharmacokinetics.