Common questions / answered from the record
PT-141 Questions, Answered From the Record
Direct, cited answers on PT-141 (bremelanotide) — the mechanism, the approved use, the dose, the duration, and the approval limits.
What is PT-141?
PT-141 is a synthetic alpha-MSH analogue that agonizes melanocortin receptors (MC3R/MC4R) expressed primarily in the central nervous system [1]. Systemic administration produced penile erections in rats and nonhuman primates and activated hypothalamic neurons, indicating a central mechanism [1]. Its nonproprietary name is bremelanotide.
What is PT-141 peptide?
PT-141 peptide is a synthetic cyclic heptapeptide — seven amino acids in a lactam ring — built as a stable analogue of alpha-MSH [1]. The ring makes it steadier than linear melanocortin peptides. It activates central MC4R/MC3R rather than acting on peripheral blood vessels [1].
What does the PT-141 peptide do?
The PT-141 peptide activates central melanocortin receptors, chiefly MC4R in the hypothalamus, engaging dopamine pathways tied to sexual desire [1][5]. In a human fMRI study, MC4R agonism raised sexual desire for up to 24 hours and shifted sexual brain processing [5]. It works in the brain, not on vascular tissue [12].
What is PT-141 used for?
PT-141 (bremelanotide) is FDA-approved for one use only: acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, at 1.75 mg subcutaneous as-needed [7][10]. Use in men, postmenopausal women, or for performance is off-label or investigational, not approved [1].
Is PT-141 the same as bremelanotide?
Yes. PT-141 is the development code and bremelanotide is the international nonproprietary name (INN) for the same melanocortin receptor agonist [10]. The approved injectable form is bremelanotide; "PT-141" sold as a research chemical is the same molecule name but sits outside the approval framework [13].
What is bremelanotide?
Bremelanotide is the INN for PT-141, a synthetic cyclic heptapeptide melanocortin (MC3R/MC4R) receptor agonist [10]. It was FDA-approved in June 2019 (NDA 210557) for HSDD in premenopausal women at 1.75 mg subcutaneous as-needed [7][10]. It acts centrally in the brain on sexual-desire circuitry [1].
What are the benefits of PT-141?
In the Phase 3 RECONNECT trials (n=1267 premenopausal women with HSDD), bremelanotide improved sexual desire (FSFI-desire +0.35, P<.001) and reduced desire-related distress (FSDS-DAO item 13 −0.33, P<.001) versus placebo [3]. The benefit was statistically significant but modest, and was sustained over 52 weeks [4].
How does PT-141 work?
PT-141 activates central melanocortin MC4R (and MC3R) receptors in the hypothalamus, engaging dopaminergic pathways governing sexual desire [1]. Unlike PDE-5 inhibitors, which act on peripheral vascular smooth muscle, it works on the brain circuitry of sexual motivation [12]. Human fMRI confirms it alters central sexual brain processing [5].
What receptors does PT-141 act on?
PT-141 is an agonist at the central melanocortin receptors MC4R and MC3R, expressed primarily in the CNS [1]. MC4R in hypothalamic circuits (e.g., the medial preoptic area) is the principal target for its sexual-desire effect; peripheral MC1R activation underlies the hyperpigmentation seen with repeated dosing [7].
Does PT-141 work through the brain or through blood flow?
Through the brain. PT-141 activates central MC4R/MC3R receptors and engages hypothalamic desire circuits [1]. In rabbit tissue, alpha-MSH relaxed vaginal-wall and artery preparations but bremelanotide (1 µM) did not, confirming it does not act directly on peripheral vascular smooth muscle [12].
What is a melanocortin receptor agonist?
A melanocortin receptor agonist is a molecule that activates the melanocortin receptors (MC1R–MC5R), a family of five receptors responding to peptides like alpha-MSH [1]. PT-141 targets the central subtypes MC3R and MC4R, which regulate sexual desire and appetite [1]. See how PT-141 works for the full pathway.
Does PT-141 increase testosterone?
No. PT-141 does not act through the HPG (testosterone) axis and does not directly raise testosterone — a common misconception [the controversies record]. It is a central melanocortin receptor agonist acting on brain desire circuits [1], mechanistically distinct from any hormonal androgen pathway.
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 MC4R/MC3R receptors in the brain to influence sexual desire [1]. In rabbit tissue, bremelanotide (1 µM) did not relax vascular preparations that alpha-MSH did, confirming the non-vascular mechanism [12].
What is the PT-141 dosage?
The US prescribing information specifies the approved bremelanotide dose: 1.75 mg subcutaneous as-needed, no more than one dose per 24 hours and no more than eight per month, for HSDD in premenopausal women [7]. This is a labeled dose for an approved use, reported here as documentation — not a recommendation.
How much PT-141 should I take?
This site does not recommend a dose for anyone. The only labeled figure is the approved 1.75 mg subcutaneous as-needed bremelanotide dose for HSDD in premenopausal women, with a one-dose/24 h and eight-doses/month cap [7]. It is documented here as the label record, not as guidance for any individual.
How much PT-141 to inject?
The labeled injection dose for the approved HSDD indication is 1.75 mg subcutaneous as-needed, capped at one dose per 24 hours and eight per month [7]. That figure applies to the approved prescription form and population only; it is reported as documentation, not a recommendation, and does not apply to off-label or research-chemical use.
What is the PT-141 dosage for women?
The labeled PT-141 dosage for women is 1.75 mg subcutaneous as-needed, for premenopausal women with acquired, generalized HSDD [7][10]. Phase 2 dose-finding tested 0.75, 1.25, and 1.75 mg before 1.75 mg was selected. Postmenopausal women are outside the approved population; no labeled dose applies to them.
How do you reconstitute PT-141?
The approved bremelanotide product is supplied as a ready-to-use subcutaneous injection, not a powder the patient reconstitutes [7]. "Research chemical" PT-141, by contrast, sits outside the approval framework with no verified identity, purity, or concentration [13]. This site documents the approved product and does not provide preparation instructions.
How do you take PT-141?
On the label, the approved bremelanotide form is given as a 1.75 mg subcutaneous injection, as needed, at least 45 minutes before anticipated activity, capped at one dose per 24 hours and eight per month [7]. This is reported as the labeled administration record for the approved use, not as instruction for any individual.
How often can you take PT-141?
The label caps the approved bremelanotide dose at one per 24 hours and no more than eight per month [7]. In the 52-week extension, this as-needed schedule sustained the desire benefit with no new safety signals, though nausea (40.4%) remained the leading tolerability issue [4]. This describes the label and trial record, not a recommendation.
What is the approved bremelanotide dose?
The approved bremelanotide dose is 1.75 mg subcutaneous as-needed, for HSDD in premenopausal women, per NDA 210557 (approved June 21, 2019) [7][10]. In the two RECONNECT trials at this dose, desire improved (FSFI-desire +0.35, P<.001) and distress fell (FSDS-DAO item 13 −0.33, P<.001) versus placebo [3].
How long does PT-141 last?
By label pharmacokinetics, the terminal half-life is about 2.7 hours (range 1.9–4.0 h) after subcutaneous dosing, with Tmax around 0.5–1.0 h [7]. The plasma half-life differs from reported subjective duration: a human fMRI study observed increased desire for up to 24 hours [5]. See PT-141 dosage for the full PK record.