FAQ · Direct answers
Frequently Asked Questions About PT-141
Short, cited answers to the questions people actually ask about PT-141 — dosage, half-life, mechanism, routes, and regulatory status.
Is PT-141 FDA-Approved?
Yes, but narrowly. Bremelanotide — the approved name for PT-141 — was FDA-approved in June 2019 (NDA 210557) as a subcutaneous injection for acquired, generalized HSDD in premenopausal women [3][13]. Every other use, including in men, for erectile dysfunction, or in postmenopausal women, is off-label and not covered by the approval [13].
What is the PT-141 dosage?
Reported only as study and label findings: the US prescribing information 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 [13]. This is a documented regimen, not a recommendation to follow.
How much PT-141 should I take?
Phase 2 subcutaneous dose-finding in women evaluated 0.75, 1.25, and 1.75 mg, and 1.75 mg was advanced to the Phase 3 program and the label [9]. These are research and label doses; this digest summarizes findings and recommends no dose for any individual.
How much PT-141 to inject?
The approved subcutaneous regimen is a single 1.75 mg dose as needed, capped at one per 24 hours [13]. Early development also studied intranasal and intravenous routes before the subcutaneous formulation was selected [6][7].
What is the PT-141 dosage for women?
For the approved indication (HSDD in premenopausal women), the label dose is 1.75 mg subcutaneously, as needed, no more than once per 24 hours and no more than 8 times per month [13]. The dose-finding trial that supported it compared 0.75, 1.25, and 1.75 mg [9].
How do you reconstitute PT-141?
The approved finished product is a prefilled subcutaneous autoinjector, not a reconstituted powder; the cyclic lactam structure is more stable than linear melanocortin peptides [13]. Material sold as "PT-141 research chemical" is for laboratory use only and is not the approved drug product [13].
How do you take PT-141?
In the pivotal trials and the label, bremelanotide is given subcutaneously as a single as-needed dose at least 45 minutes before anticipated activity [6][13]. Intranasal delivery was used in early development but discontinued due to pharmacokinetic variability [6].
How often can you take PT-141?
The label limits use to no more than one 1.75 mg dose per 24 hours and no more than 8 doses per month [13]. The frequency cap reflects tolerability findings, including nausea, and the transient blood-pressure effect seen with dosing [4][13].
What is the approved bremelanotide dose?
Per the US prescribing information, the approved bremelanotide dose is 1.75 mg subcutaneous, as needed, with a maximum of one dose per 24 hours and 8 doses per month, for acquired, generalized HSDD in premenopausal women [13].
How long does PT-141 last?
The terminal half-life after subcutaneous dosing is about 2.7 hours (range 1.9–4.0 h) per the prescribing information, with a median Tmax of roughly 0.5–1.0 hour [13]. Pharmacodynamic effects on desire were measured for up to 24 hours in a mechanistic imaging study, so the experienced effect can outlast plasma levels [5].
How long does PT-141 take to work?
Subcutaneous bremelanotide reaches median peak concentrations within about 0.5–1.0 hour, and the label directs dosing at least 45 minutes before anticipated activity [13]. In early intranasal erectile-dysfunction research, the first erection was reported at roughly 30 minutes [6].
What is the half-life of PT-141?
The US prescribing information reports a terminal half-life of approximately 2.7 hours (range 1.9–4.0 h) after subcutaneous administration; early intranasal studies reported 1.85–2.09 hours [6][13]. Volume of distribution is about 25 L and clearance about 6.5 L/hr [13].
How long does PT-141 stay in your system?
With a terminal half-life near 2.7 hours, the bulk is cleared within roughly a day [13]. Metabolism is by hydrolysis of the cyclic-peptide bonds and peptidase digestion, with excretion about 64.8% renal and 22.8% fecal in a radiolabeled study [13].
Does PT-141 nasal spray work?
Early intranasal PT-141 produced a dose-dependent erectile response above 7 mg in men, but the intranasal program was discontinued because of pharmacokinetic variability, and development moved to the subcutaneous route that was ultimately approved [6][13].
What is PT-141?
PT-141 is the research designation for bremelanotide, a synthetic cyclic heptapeptide analogue of alpha-MSH that activates central melanocortin receptors (MC3R/MC4R) [1]. It is FDA-approved as bremelanotide injection only for HSDD in premenopausal women [13].
What is PT-141 peptide?
It is a synthetic cyclic seven-amino-acid peptide — a lactam analogue of alpha-melanocyte-stimulating hormone — that acts as a melanocortin MC3R/MC4R agonist in the brain rather than on blood vessels [1].
What does the PT-141 peptide do?
By activating melanocortin MC4R (and MC3R) receptors in hypothalamic and limbic circuits, PT-141 engages central pathways tied to sexual desire and arousal, a mechanism distinct from the peripheral vascular action of PDE-5 inhibitors [1][5].
What is PT-141 used for?
Its single FDA-approved use is acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women [3][13]. Use in men, for erectile dysfunction, in postmenopausal women, or for sexual performance is off-label and, for the male/erectile setting, supported only by early-phase research [6].
Is PT-141 the same as bremelanotide?
Yes. Bremelanotide is the international nonproprietary name (INN) for the same molecule that the research literature calls PT-141; the approved injectable drug product is bremelanotide [13].
What is bremelanotide?
Bremelanotide is the approved-drug name for PT-141, a melanocortin MC3R/MC4R receptor agonist approved by the FDA in June 2019 for HSDD in premenopausal women and administered as a 1.75 mg subcutaneous injection as needed [3][13].
How does PT-141 work?
PT-141 is an alpha-MSH analogue that agonizes melanocortin MC4R and MC3R receptors in the hypothalamus (including the medial preoptic area) and limbic system, engaging dopaminergic circuitry linked to sexual motivation rather than acting on vascular tone [1][5].
What receptors does PT-141 act on?
Its primary central targets are the melanocortin 4 receptor (MC4R) and, secondarily, the melanocortin 3 receptor (MC3R) [1]. Peripheral MC1R activation is the basis for the hyperpigmentation seen with repeated dosing [13].
Does PT-141 work through the brain or through blood flow?
Through the brain. PT-141 acts centrally on melanocortin receptors in hypothalamic and limbic circuits, unlike PDE-5 inhibitors such as sildenafil and tadalafil, which act peripherally on penile vascular smooth muscle to support blood flow [1][8].