Research archive · The numbers
PT-141 Dosage Research, Routes, and Half-Life
What the studies and the approved label document about dose, delivery, and how long it lasts — reported as research, not as instructions.
The short version
This page summarizes PT-141 dosage as documented in the studies and the approved drug label — it does not tell anyone what to take. The one approved dose is for women: 1.75 mg injected under the skin, used as needed, at least 45 minutes before sex, with no more than one dose in 24 hours and no more than eight doses a month [7].
How long does it last in the body? After the injection, PT-141 has a half-life (the time for half of it to clear) of about 2.7 hours, ranging roughly 1.9 to 4.0 hours [7]. It is delivered as a subcutaneous injection in the approved form; earlier research also tried a nasal spray and an intravenous route [7][8]. There is no approved male dose, because PT-141 is not approved for men [7]. Everything below is study-attributed.
PT-141 dosage in the research
The doses that appear in the literature are research and label doses, not recommendations. The approved label dose is 1.75 mg subcutaneously, as needed, capped at one dose per 24 hours and eight per month [7]. Phase 2 dose-finding in women tested 0.75, 1.25, and 1.75 mg before the 1.75 mg dose was chosen [7].
In the early male research, a nasal spray was escalated to roughly 7 to 20 mg, with a statistically significant erectile response appearing above 7 mg [8]. Separate Phase 1 metabolic research in women used subcutaneous doses up to 2.5 mg, several times daily for 15 days, strictly as a research protocol [7]. These figures describe what was given to whom in studies — they are not a guide for any individual, and this site recommends no dose.
How long does PT-141 last
How long does PT-141 last has two answers: how long it stays in the body, and how long an effect was observed. In the body, the approved subcutaneous form has a terminal half-life of about 2.7 hours (range 1.9 to 4.0 hours) [7]; early nasal studies reported a slightly shorter 1.85 to 2.09 hours [8]. Peak blood levels arrive quickly — a median of about 0.5 to 1.0 hours after a subcutaneous injection [7].
The observed effect can outlast the drug in the blood. In the 2022 brain-imaging study, a single dose increased desire for up to 24 hours — longer than the molecule itself lingers — because the effect is a downstream brain change, not just the presence of the drug [5]. In the early male nasal studies, first erections appeared at about 30 minutes [8]. Other label pharmacokinetics: a volume of distribution near 25 L, clearance about 6.5 L/hr, and excretion mostly via the kidneys (about 65%) and feces (about 23%) [7].
PT-141 dosage for women
The PT-141 dosage for women is the only one with regulatory backing, and it is the approved label dose: 1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated sexual activity, with the same caps of one dose per 24 hours and eight per month [7]. That dose was selected from the Phase 2 range (0.75 to 1.75 mg) and carried into the two Phase 3 trials [3][7].
It is approved specifically for premenopausal women with acquired, generalized HSDD, and not for postmenopausal women [7]. The label also carries the blood-pressure caution: people with uncontrolled high blood pressure or known cardiovascular disease should not use it because of a transient post-dose blood-pressure rise [7]. As everywhere on this site, this describes the label — it is not personal medical advice, and no dose is recommended to any reader.