GW590735 is a potent and selective agonist of PPARα with an EC50 value of 4 nM for the expression a GAL4-responsive reporter gene and at least 500-fold selectivity versus PPARγ and PPARδ. GW590735 significantly increased HDL cholesterol, decreased LDL and VLDL cholesterol, and significantly reduced triglycerides. Maximal increases in HDL cholesterol were 37%, 53%, and 84% with fenofibrate, torcetrapib, and GW590735, respectively.