PT-141 (Bremelanotide)

An FDA-approved melanocortin receptor agonist derived from Melanotan II, specifically developed for sexual dysfunction research with central nervous system mechanism.

View on Iron Peak Peptides →

Overview

PT-141, known by its generic name Bremelanotide, is a cyclic heptapeptide melanocortin receptor agonist derived from Melanotan II. It acts primarily on MC3R and MC4R in the central nervous system to modulate sexual arousal pathways. PT-141 is notable as the first FDA-approved treatment for hypoactive sexual desire disorder (HSDD) in premenopausal women (approved in 2019 under the brand name Vyleesi®).

Unlike phosphodiesterase-5 inhibitors (e.g., sildenafil) that act peripherally on vascular smooth muscle, PT-141 works through a unique central mechanism — activating melanocortin circuits in the hypothalamus that regulate sexual desire and arousal. This central mechanism of action makes it a groundbreaking research compound for understanding the neurobiology of sexual function.

Mechanism of Action

PT-141 acts as an agonist at MC3R and MC4R melanocortin receptors in the central nervous system, particularly within hypothalamic nuclei involved in sexual behavior regulation (medial preoptic area, paraventricular nucleus).

MC4R activation in the paraventricular nucleus triggers a signaling cascade that ultimately increases oxytocin release and activates descending autonomic pathways to the spinal cord. This enhances both the psychogenic (desire/arousal) and reflexogenic (genital blood flow) components of sexual response.

The MC3R activation contributes to motivational and reward aspects of sexual behavior through dopaminergic pathway modulation in the mesolimbic system. PT-141 was specifically engineered from Melanotan II to retain the sexual function effects while minimizing pigmentation activity, though some residual MC1R activation may occur at higher doses.

Key Research Findings

• FDA Approval for HSDD: Phase III clinical trials demonstrated statistically significant improvements in sexual desire and reduction of distress associated with low desire in premenopausal women, leading to FDA approval in June 2019.
• Central Mechanism Confirmed: Neuroimaging studies confirm that PT-141 activates hypothalamic and limbic brain regions associated with sexual arousal, distinguishing it from peripherally-acting agents.
• Efficacy in Both Sexes: Research has demonstrated pro-sexual effects in both male and female models, including improved erectile function in male subjects with psychogenic erectile dysfunction.
• Rapid Onset: Studies show onset of action within approximately 45-60 minutes following subcutaneous administration, with peak effects at 1-3 hours.
• Nausea as Primary Side Effect: Nausea is the most commonly reported adverse effect in clinical studies, occurring in approximately 40% of subjects, typically mild and transient.

Research Applications

• Sexual function and dysfunction research
• Melanocortin receptor neurobiology studies
• Central vs. peripheral sexual arousal pathway research
• Hypothalamic-autonomic integration studies
• Female sexual desire and arousal research
• Melanocortin-oxytocin pathway interaction studies

Dosing Protocols (Research Use Only)

Note: Dosing information is compiled from published research literature and is intended for reference purposes only.

Ready to Research PT-141 (Bremelanotide)?

Get ≥99% purity research-grade peptides with COA from Iron Peak Peptides.

Shop PT-141 (Bremelanotide) →