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PT-141, Frequently Asked
The questions people actually search, answered plainly and cited where there's a number.
What is PT-141?
PT-141 is the research designation for bremelanotide, a synthetic cyclic heptapeptide that copies the natural hormone alpha-MSH and activates central melanocortin MC3R/MC4R receptors [1]. It's FDA-approved (June 2019) for one use only: hypoactive sexual desire disorder (HSDD) in premenopausal women [6].
What is PT-141 peptide?
It's a melanocortin (MC3R/MC4R) receptor agonist peptide — the same molecule as bremelanotide [1]. Its cyclic ring of seven amino acids makes it sturdier than a straight-chain melanocortin peptide, which helps it last longer in the body.
What does the PT-141 peptide do?
It activates melanocortin receptors in the brain — chiefly MC4R — in circuits tied to sexual desire and arousal, acting centrally rather than on blood flow [1]. In the approved population, it improved sexual desire and reduced desire-related distress in the Phase 3 RECONNECT trials [3].
What is PT-141 used for?
Its single FDA-approved use is acquired, generalized HSDD in premenopausal women [6]. Every other use — in men, for erectile dysfunction, in postmenopausal women, or for sexual performance — is off-label and supported only by early-phase or investigational research [6].
Is PT-141 the same as bremelanotide?
Yes. "PT-141" is the original research designation and "bremelanotide" is the international nonproprietary name (INN) for the same melanocortin receptor agonist that the FDA approved for HSDD [6]. Two names, one molecule.
What is bremelanotide?
Bremelanotide is the approved-drug name for PT-141: a melanocortin MC3R/MC4R receptor agonist approved in June 2019 as a 1.75 mg subcutaneous injection for HSDD in premenopausal women [6]. It acts on brain circuits for desire, not on blood flow [1].
How does PT-141 work?
It stimulates central melanocortin receptors, mainly MC4R in hypothalamic and limbic circuits such as the medial preoptic area, which engages dopamine pathways governing sexual motivation [1]. This central mechanism is distinct from PDE-5 inhibitors, which act peripherally on vascular blood flow.
What receptors does PT-141 act on?
Primarily the melanocortin 4 receptor (MC4R), with secondary activity at MC3R, both concentrated in the central nervous system [1]. Peripheral MC1R activation is what underlies the hyperpigmentation seen with repeated dosing [6].
Does PT-141 work through the brain or through blood flow?
Through the brain. PT-141 acts centrally on melanocortin circuits governing sexual desire, unlike PDE-5 inhibitors, which act peripherally on vascular smooth muscle to increase blood flow [1]. A 2022 fMRI study in women with HSDD showed MC4R agonism altered task-based brain processing of erotic stimuli [5].
What is a melanocortin receptor agonist?
A compound that activates one or more of the five melanocortin receptors (MC1R–MC5R), which respond to peptides like alpha-MSH [1]. PT-141 is an agonist targeting the central MC3R and MC4R subtypes [1].
Does PT-141 increase testosterone?
No. A common misconception is that PT-141 raises testosterone or works through the HPG axis [1]. It acts on central melanocortin receptors and is not a hormone-replacement agent or a PDE-5 inhibitor.
How is PT-141 different from PDE-5 inhibitors?
PDE-5 inhibitors act peripherally on vascular smooth muscle to improve erectile blood flow. PT-141 acts centrally on melanocortin receptors in brain circuits for sexual desire and arousal — a fundamentally different mechanism [1]. Combining the two, centrally and peripherally, is the basis of an active erectile-dysfunction research program [9].
What is the PT-141 dosage?
Reported only as the approved label, not as advice: the US prescribing information specifies bremelanotide 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 for HSDD in premenopausal women [6].
How much PT-141 should I take?
This digest reports doses only as study and label findings and recommends no dose for any individual. The approved label dose for HSDD in premenopausal women is 1.75 mg subcutaneous as needed [6]; any other use is off-label and unstudied as a self-administered protocol.
How much PT-141 to inject?
Reported as a finding: the approved bremelanotide regimen is a single 1.75 mg subcutaneous injection as needed for HSDD in premenopausal women [6]. Phase 2 dose-finding in women evaluated 0.75, 1.25, and 1.75 mg [3]. These are trial and label figures, not dosing instructions.
What is the PT-141 dosage for women?
The approved label for premenopausal women with HSDD specifies 1.75 mg subcutaneously as needed, with a maximum of one dose per 24 hours and no more than 8 per month [6]. Reported here as the regulatory finding, not as a recommendation.
How do you reconstitute PT-141?
The approved finished product is supplied as a prefilled subcutaneous autoinjector and is not reconstituted by the user [6]. Material sold as "PT-141 research chemical" is a laboratory reagent, not the approved drug; this digest does not provide reconstitution or self-administration instructions.
How do you take PT-141?
In the approved indication, bremelanotide is given subcutaneously as a single as-needed dose at least 45 minutes before anticipated activity [6]. The early intranasal formulation was discontinued for pharmacokinetic variability [6]. Reported as label and development facts, not as a protocol for a reader to follow.
How often can you take PT-141?
Reported as the approved label limit, not as advice: no more than one 1.75 mg subcutaneous dose per 24 hours and no more than 8 doses per month for HSDD in premenopausal women [6].
What is the approved bremelanotide dose?
1.75 mg subcutaneously, as needed, for acquired generalized HSDD in premenopausal women, with a ceiling of one dose per 24 hours and 8 per month, per the US prescribing information [6].
How long does PT-141 last?
The prescribing information reports a terminal half-life of about 2.7 hours (range 1.9–4.0 h) after subcutaneous administration, with a median Tmax around 0.5–1.0 hour [6]. Reported as a pharmacokinetic finding.