PT-141
Bremelanotide / Vyleesi
PT-141 (Bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist derived from Melanotan II, developed specifically to isolate the sexual function effects from the tanning properties of its parent compound. It was FDA-approved in 2019 under the brand name Vyleesi for treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women, making it one of the few peptides to achieve full regulatory approval. PT-141 works centrally through melanocortin-4 receptor (MC4R) activation in the hypothalamus rather than through vascular mechanisms like PDE5 inhibitors.
Mechanism of Action
Melanocortin-4 receptor (MC4R) agonist derived from Melanotan II. Acts centrally in the hypothalamus to increase sexual desire and arousal through dopaminergic pathways. Unlike PDE5 inhibitors, works on desire rather than mechanical erectile function.
Research Protocols
For research purposes only. Not medical advice.
Research protocols use 1-2mg via subcutaneous injection 45 minutes before anticipated activity. Maximum frequency: once per 24 hours, no more than 8 times per month. FDA-approved dose for HSDD is 1.75mg.
Research Notes
Clinical Research Status
PT-141 received FDA approval in June 2019 as Vyleesi (bremelanotide) for HSDD in premenopausal women, administered as a 1.75mg subcutaneous auto-injector used as-needed before sexual activity. Phase 3 RECONNECT trials demonstrated statistically significant improvements in sexual desire and reduction in distress compared to placebo. Research continues into male erectile dysfunction applications, where it has shown efficacy in patients who do not respond to PDE5 inhibitors.
Key Published Findings
Clinical trials showed that PT-141 increased the number of satisfying sexual events and improved desire scores in women with HSDD over 24-week treatment periods. In male ED studies, it produced erections in men unresponsive to sildenafil, confirming its unique central mechanism of action. Functional MRI studies demonstrate that PT-141 activates brain regions associated with sexual arousal, distinguishing it mechanistically from all other sexual dysfunction treatments.
Safety Profile
The most common side effect is nausea, occurring in approximately 40% of patients and typically diminishing with repeated use. Flushing, headache, and transient hypertension are reported in 10-20% of users. The FDA label carries a warning about transient blood pressure increases and recommends against use in patients with uncontrolled hypertension or cardiovascular disease. Dosing is limited to no more than once every 24 hours and no more than 8 doses per month.
Drug Interactions & Contraindications
PT-141 may cause additive hypotension when combined with naltrexone or other opioid antagonists used for HSDD treatment. Not recommended for use with other melanocortin receptor agonists due to overlapping receptor activity. Contraindicated in uncontrolled hypertension and should be used cautiously with antihypertensive medications due to unpredictable blood pressure effects.
Comparison to Related Compounds
Unlike PDE5 inhibitors (sildenafil, tadalafil) which work peripherally on vascular smooth muscle, PT-141 acts centrally on sexual desire and arousal pathways in the brain. Derived from Melanotan II but engineered to minimize melanocortin-1 receptor activity (tanning) while preserving MC4R activity (sexual function). It is the only FDA-approved treatment that directly targets the neurological component of sexual desire rather than the mechanical vascular response.
Community Observations
Research dosing for males typically ranges from 500mcg to 2mg subcutaneously, administered 2-4 hours before anticipated sexual activity. Nausea management is the primary challenge, with many users reporting that starting at lower doses (250-500mcg) and titrating up reduces initial GI side effects. Effects typically onset within 1-3 hours and can persist for 6-12 hours, with some users reporting residual effects lasting up to 72 hours.
Half-Life
~2-3 hours
Reconstitution
Bacteriostatic water (BAC)
Storage
Lyophilized
Refrigerate 2-8C up to 24 months.
Reconstituted
Refrigerate 2-8C. Use within 30 days.
US Legal Status
Also Known As
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