Research digest · 03
PT-141 dosage, read as published findings — the label regimen, the trial doses, and the pharmacokinetics
Doses appear here only as study and label findings. This digest recommends no dose for any individual.
The gist
This page reports PT-141 dosage as facts from the label and the trials — not as instructions. The approved product for premenopausal women with HSDD is 1.75 mg injected just under the skin (subcutaneous), taken as needed, with a cap of one dose per 24 hours and eight per month. It reaches its peak in the blood fast (about half an hour to an hour) and clears with a terminal half-life of roughly 2.7 hours. The approved product is a ready-to-use autoinjector, so it is not mixed or reconstituted. Material sold as "research chemical" is a different, unapproved thing. Read everything here as published findings; nothing on this page is a protocol to follow.
PT-141 Dosage in the Research and on the Label
The approved label specifies PT-141 dosage as 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 8 doses per month [6]. That is the authoritative regimen, and it is reported here as a label finding — not as guidance for any reader.
The development history fills in the range. Phase 2 subcutaneous dose-finding in women studied 0.75, 1.25, and 1.75 mg before the 1.75 mg dose advanced to Phase 3 [6]. Early intranasal research in men with erectile dysfunction used dose-escalation to roughly 7-20 mg, with a statistically significant erectile response above 7 mg — but the intranasal route was later discontinued due to pharmacokinetic variability, and that work was early-phase only [1]. A separate Phase 1 obesity research protocol administered subcutaneous doses up to 2.5 mg, up to three times daily for 15 days — a research protocol, not an approved or recommended regimen [6].
PT-141 Dosage for Women in the Approved Indication
In the approved indication — premenopausal women with HSDD — the regimen is 1.75 mg subcutaneous, as needed, with a maximum of one dose per 24 hours and 8 doses per month [6]. This is the only population for which a dose is approved, and it is stated here as a label finding.
PT-141 as a Subcutaneous Injection
The approved PT-141 injection is subcutaneous — delivered just under the skin via a prefilled, ready-to-use autoinjector [6]. The earlier intranasal formulation was discontinued in development because of pharmacokinetic variability, leaving the subcutaneous route as the approved one [1]. The injection delivers a fixed 1.75 mg dose.
How long PT-141 lasts and how fast it acts
How Long PT-141 Lasts
PT-141 clears relatively quickly. Terminal half-life 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]. The pharmacological signal can outlast the drug in plasma, though — the crossover fMRI study reported increased sexual desire for up to 24 hours after a single dose [5].
PT-141 Half-Life
The terminal half-life is approximately 2.7 hours (range 1.9-4.0 h) per the US prescribing information [6]. Supporting pharmacokinetics: volume of distribution ~25.0 L, clearance ~6.5 L/hr, ~21% serum protein binding, with excretion 64.8% renal and 22.8% fecal from a radiolabeled dose [6].
Onset is fast. Median Tmax — the time to peak blood concentration — is about 0.5-1.0 hour after subcutaneous injection, which is why the label situates dosing at least 45 minutes before anticipated activity [6]. Metabolism proceeds by hydrolysis of the cyclic-peptide amide bonds and peptidase digestion [6].
Dosing questions, answered as findings
What is the PT-141 dosage?
The approved label specifies 1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated activity, with no more than one dose per 24 hours and no more than 8 doses per month [6]. This is reported as a label finding, not a recommendation; material sold as "PT-141 research chemical" is for laboratory use only.
How much PT-141 should I take?
This site reports doses only as study and label findings, not as guidance for any individual. The approved bremelanotide regimen for HSDD in premenopausal women is 1.75 mg subcutaneous as needed; Phase 2 dose-finding studied 0.75, 1.25, and 1.75 mg [6].
How much PT-141 to inject?
The approved subcutaneous dose in the label is 1.75 mg as needed (maximum one dose per 24 hours, 8 per month) [6]. Reported here as a published finding only; no dosing protocol is recommended for readers.
How do you reconstitute PT-141?
The approved bremelanotide product is supplied as a prefilled, ready-to-use subcutaneous autoinjector, so it is not reconstituted [6]. Lyophilized "research chemical" powder is a different, unapproved material; this digest does not provide reconstitution or self-administration instructions.
How do you take PT-141?
In the approved indication it is given as a subcutaneous injection, as needed, at least 45 minutes before anticipated sexual activity [6]. Median onset to peak concentration is about 0.5-1.0 hour [6]. Described as a label finding, not as instructions to self-administer.
Field reports (not clinical data)
Unverified community reports follow — included for context, not as evidence, and not as advice. None of this is from a journal, tied to a PMID, or measured in a trial, and nothing here is a dosing protocol or an encouragement to self-administer.
What people commonly describe lines up with the cited pharmacokinetics without adding to them: a fast onset, with effects discussed in a same-day, as-needed frame rather than a daily one, consistent with the short half-life and the roughly half-hour-to-hour time-to-peak in the cited label [6]. The cautions researchers pass around most often are timing the injection ahead of activity, the nausea that frequently accompanies onset, and — with frequent repeat dosing — a transient skin-darkening warning that echoes the MC1R hyperpigmentation in the cited label [6]. Any "reported dose" mentioned in community settings is an anecdote, explicitly not a recommendation; the only approved dose is the 1.75 mg subcutaneous as-needed regimen above [6].