TAS2R1 encodes a bitter taste receptor that plays a crucial role in detecting bitter compounds both in oral and extraoral tissues. The receptor functions as a G-protein coupled receptor linked to gustducin signaling, mediating calcium mobilization upon ligand binding 1. TAS2R1 is activated by diverse bitter compounds including pharmaceutical agents such as nirmatrelvir (causing 'Paxlovid mouth'), lopinavir, ritonavir, and tenofovir alafenamide 234. The receptor also responds to natural bitter substances like amarogentin and olive oil phenolics, particularly oleuropein aglycon and ligstroside aglycon 56. Beyond taste perception, TAS2R1 exhibits broader physiological functions including regulation of keratinocyte differentiation in skin and immunomodulatory effects in mast cells 15. The receptor is expressed extraorally in various tissues including skin keratinocytes, where it colocalizes with α-gustducin and influences cellular differentiation markers 1. Clinically, TAS2R1 activation by medications contributes to treatment adherence challenges, particularly in pediatric populations, making it a target for developing bitter taste blockers to improve medication compliance 34.