VPR-66

**VPR-66** is a synthetic small molecule inhibitor designed to target the ligand-binding domain (LBD) of retinoic acid receptor-related orphan receptors (RORs), specifically acting as an inverse agonist for **RORα** and **RORγt**. Developed through molecular modeling studies, it partially reverses the anti-senescence and circadian rhythm-enhancing effects of bavachalcone in human endothelial cells by blocking RORα-mediated induction of Bmal1 expression and suppression of senescence markers like p16^INK4a and IL-1α. It is commercially available from suppliers such as Novus Biologicals (NBP2-29335) strictly for research use and has no approved therapeutic indications or clinical development status.[1][8][11][13]