PT-141
A synthetic melanocortin receptor agonist studied for central nervous system effects on sexual arousal, libido, and sexual response.
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What is PT-141?
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide and analog of α-melanocyte stimulating hormone (α-MSH), developed by Palatin Technologies as a research compound investigating melanocortin receptor pharmacology in sexual function. The peptide was originally derived from research on Melanotan 2 — another melanocortin receptor agonist developed for tanning research — when unexpected sexual response effects were observed in clinical studies. PT-141 was developed by structurally modifying Melanotan 2 to eliminate the tanning effect while preserving the sexual response activity, producing a peptide with selectivity for the central effects relevant to libido and arousal.
PT-141 is notable in research as the first peptide to receive FDA approval specifically for sexual function, marketed as Vyleesi for hypoactive sexual desire disorder in premenopausal women. The compound acts through central nervous system pathways rather than peripheral vascular effects (distinguishing it from PDE5 inhibitors like sildenafil), affecting the brain regions involved in sexual arousal and motivation. Research has examined applications in both female and male sexual dysfunction across various contexts.
Mechanism of action
PT-141’s mechanisms of action have been investigated across multiple pathways:
- Melanocortin receptor activation: The peptide acts as an agonist primarily at the MC3R and MC4R melanocortin receptors expressed in the central nervous system, particularly in the hypothalamus and other brain regions involved in sexual arousal and motivation.
- Central nervous system effects on sexual processing: Unlike PDE5 inhibitors that act peripherally on vascular smooth muscle, PT-141 acts centrally on brain regions involved in sexual desire, arousal, and motivational aspects of sexual response.
- Dopaminergic system interaction: Research has documented effects on dopamine release in brain regions associated with reward and motivation, contributing to the libido-enhancing effects observed in research models.
- Reduced melanocortin-1 receptor activity: Through structural modifications from Melanotan 2, PT-141 has reduced activity at MC1R (responsible for melanogenesis), minimizing the tanning effects that characterize less selective melanocortin agonists.
- Effects independent of vascular pathways: The peptide does not produce significant peripheral vascular effects, distinguishing it mechanistically from vasodilatory approaches to sexual function research.
These pathways are characterized in both preclinical models and human clinical research.
Research applications
PT-141 has been investigated across several research domains, with the most active areas including:
- Female sexual dysfunction research: The most clinically developed research application examined effects on hypoactive sexual desire disorder in premenopausal women. The RECONNECT clinical trial program documented improvements in sexual desire and reductions in distress related to low desire, supporting FDA approval as Vyleesi.
- Male erectile dysfunction research: Earlier clinical research examined PT-141 in male erectile dysfunction, with studies demonstrating effects on erectile function through central nervous system mechanisms distinct from PDE5 inhibitor pathways.
- Sexual response mechanism research: PT-141 has served as a research tool for studying central nervous system contributions to sexual response, contributing to understanding of the neural circuits underlying sexual desire and arousal.
- Melanocortin receptor pharmacology research: Studies have examined PT-141’s receptor selectivity profile to better characterize the roles of different melanocortin receptors in central nervous system function.
- Combination research: Research has examined PT-141 in combination with other approaches to sexual function, exploring complementary mechanisms targeting both central arousal and peripheral vascular response.
This compound is intended for laboratory research use only. It has not been approved for human therapeutic use by any regulatory agency.
Storage & reconstitution
In its lyophilized form, PT-141 tolerates ambient temperatures during shipping but should be stored long-term at -20°C, protected from light. Properly stored lyophilized peptide remains stable for 24 months or longer.
Once reconstituted with bacteriostatic water for injection, PT-141 solutions should be stored refrigerated at 2-8°C and used within 28 days. Avoid repeated freeze-thaw cycles, which can degrade peptide structure and reduce activity.
Visual inspection should be performed before each use. The reconstituted solution should be clear and colorless. Reject any solution that appears cloudy, discolored, or contains visible particulate matter.
For step-by-step reconstitution calculations, see our reconstitution calculator.
For laboratory research use only. The compound described on this page is intended exclusively for in vitro research and laboratory experimentation by qualified researchers and is not for human or veterinary use. It is not a drug, food, dietary supplement, or cosmetic, and has not been approved by the FDA, Health Canada, EMA, or any other regulatory authority for the diagnosis, treatment, cure, mitigation, or prevention of any disease or medical condition. The information provided on this page is for educational and reference purposes only and does not constitute medical advice. By accessing this content you confirm that you are a qualified researcher purchasing for legitimate laboratory purposes.