GW501516 is a subtype-selective synthetic agonist targeting peroxisome proliferator-activated receptor delta (PPAR ) exhibiting a Ki value of approximately 1 1 nM PPAR widely expressed in various tissues mediates cholesterol metabolism and interacts with retinoid X receptor (RXR) In cellular reporter assays utilizing a GAL4-driven system GW501516 activates PPAR -dependent transcription with an EC50 value close to 1 2 nM and demonstrates roughly 1000-fold greater selectivity toward PPAR compared to other PPAR isoforms Experimental studies in primate models of metabolic disease have shown GW501516 promotes HDL-cholesterol elevation reduces fasting triglycerides modifies LDL/VLDL particle profiles to larger forms enhances cholesterol efflux via increasing ABCA1 expression and partially reduces hyperinsulinemia without adverse effects on glucose handling GW501516 serves as a research tool for exploring the mechanisms and functions of PPAR activation in metabolic regulation