Wy 14643 is a PPAR activator. Although this compound is primarily an activator of PPARα,{3458,6573,6549} it activates PPARγ as well.{4044} Activation of PPAR.delta. by Wy 14643 is also observed,{6161} but this finding is rare. The potency of Wy 14643 as an activator of PPARα is species dependent, with receptor activation occurring at concentrations as low as 0.1 μM in the mouse compared to 10 μM in Xenopus.{5592}