GW-501516, commonly referred to as Cardarine, is a synthetic compound that acts as a PPARδ (Peroxisome Proliferator-Activated Receptor Delta) agonist. It was originally developed in the 1990s by GlaxoSmithKline (GSK) and Ligand Pharmaceuticals for its potential benefits in treating metabolic and cardiovascular diseases. Although it is often grouped with SARMs due to its performance-enhancing effects, GW-501516 is not a SARM. Its primary mechanism involves modulating the expression of genes involved in energy metabolism.