Work primarily by activating a nuclear transcription receptor called PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA OR PPAR-ALPHA. increases the removal of triglycerides from circulation and their breakdown to fatty acids. decrease expression of a protein Apo-Clll (inhibits lipoprotein lipase activity). also increases expression of proteins Apo-AI and Apo-AII (major component of HDL, thus leading to increase in its concentrations). S/E: GI disturbances, Myopathy and rhabdomyolysis, increase risk of gallstone formation.