Common questions · cited where it counts
PT-141, answered plainly.
Direct answers to the questions people actually ask about bremelanotide — mechanism, receptors, dosing figures, and the exact approval scope.
What is PT-141 used for?
Bremelanotide (PT-141) is FDA-approved for one use: acquired, generalized HSDD in premenopausal women [6]. It is a melanocortin MC4R/MC3R agonist that acts centrally on sexual desire and arousal [1]. Every other use — men, erectile dysfunction, postmenopausal women — is off-label and not covered by the approval [6].
What is PT-141?
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that activates central melanocortin MC4R/MC3R receptors [1]. It is the active ingredient of an FDA-approved subcutaneous injection for HSDD in premenopausal women [6].
What is PT-141 peptide?
It is a melanocortin-agonist peptide: a cyclic heptapeptide lactam, Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, built on the alpha-MSH(4-10) sequence [1]. The cyclic structure makes it more stable than linear melanocortin peptides, which is why it survives long enough to dose as needed [1].
What does the PT-141 peptide do?
It stimulates melanocortin MC4R (and MC3R) receptors concentrated in the hypothalamus and limbic system, engaging dopaminergic circuits linked to sexual desire and arousal [1][5]. Unlike PDE-5 inhibitors, it works centrally on the neural circuitry of sexual motivation rather than peripherally on blood flow [5].
Is PT-141 the same as bremelanotide?
Yes. 'Bremelanotide' is the international nonproprietary name (INN) for the molecule called PT-141 in research settings [6]. The FDA-approved finished drug is bremelanotide injection; 'PT-141 research chemical' material is the same compound sold for laboratory use only, outside that approval [6].
What is bremelanotide?
Bremelanotide is the melanocortin MC4R/MC3R receptor agonist approved (NDA 210557, June 21, 2019) as a subcutaneous injection for acquired, generalized HSDD in premenopausal women [6]. It is the same compound as PT-141 [1].
How does PT-141 work?
By activating MC4R in hypothalamic circuits such as the medial preoptic area, PT-141 is thought to engage dopaminergic pathways governing sexual desire and arousal [1]. It is a central-nervous-system mechanism, distinct from the peripheral vascular action of PDE-5 inhibitors [5].
What receptors does PT-141 act on?
Chiefly the melanocortin 4 receptor (MC4R), with secondary melanocortin 3 receptor (MC3R) activity [1]. These are central-nervous-system melanocortin receptors; MC1R activation in skin is the separate basis for the hyperpigmentation reported with repeated frequent dosing [6].
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 that govern sexual motivation [1]. It does not act on vascular smooth muscle the way PDE-5 inhibitors do; a 2022 fMRI study tied its effect to altered central processing of sexual 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 such as alpha-MSH [1]. PT-141 targets the central MC4R and MC3R subtypes; that central action is what links it to sexual desire [1][5].
Does PT-141 increase testosterone?
No. A common misconception is that PT-141 raises testosterone or acts via the HPG axis; it does not [1]. It works on central melanocortin receptors and the dopaminergic circuitry of sexual desire, not on the gonadal hormone axis [5].
How is PT-141 different from PDE-5 inhibitors?
PDE-5 inhibitors (such as sildenafil or tadalafil) act peripherally on vascular smooth muscle to improve erectile blood flow. PT-141 acts centrally on melanocortin receptors in the brain to influence sexual desire and arousal [5]. The two mechanisms are fundamentally distinct.
What were the results of the PT-141 clinical trials?
Two identical Phase 3 RCTs (RECONNECT, n=1267 premenopausal women with HSDD) met both co-primary endpoints over 24 weeks; a 52-week open-label extension sustained the desire improvement with no new safety signals [3][4]. The most common adverse events were nausea (~40%), flushing (~21%), and headache (~12%) [4].
What is the PT-141 dosage?
For the approved HSDD indication the label specifies bremelanotide 1.75 mg subcutaneously as needed (max one dose per 24 hours, no more than 8 per month) [6]. Other doses appear only in research: Phase 2 dose-finding used 0.75-1.75 mg, and early intranasal ED studies escalated to roughly 7-20 mg [1][6]. Reported as findings, not as a protocol.
How much PT-141 should I take?
This site does not recommend a dose for any individual. The only approved figure is the label's 1.75 mg subcutaneous as-needed dose for HSDD in premenopausal women (max 1 per 24 h, 8 per month), reported here strictly as what the label and trials specify [6].
How much PT-141 to inject?
The approved label dose is 1.75 mg given subcutaneously as needed, no more than once per 24 hours and no more than 8 times per month [6]. That is the studied and labelled figure for the approved indication, not a personal-use instruction; material sold as research chemical is for laboratory use only [6].
How do you reconstitute PT-141?
The approved product is a prefilled subcutaneous autoinjector, not a reconstituted powder [6]. Lyophilized 'PT-141 research chemical' is a laboratory material for research use only; this site does not provide reconstitution or self-administration instructions.
How do you take PT-141?
The approved route is subcutaneous injection, self-administered as needed at least 45 minutes before anticipated sexual activity [6]. Early development also tried intranasal and intravenous routes; the intranasal program was discontinued for pharmacokinetic variability [6]. This describes the research and label, not a human-use instruction.