(R)-IMPP is a cell-permeable inhibitor of the secretion of proprotein convertase subtilisin/kexin type 9 (PCSK9; IC50 = 4.8 μM). It promotes the uptake of LDL cholesterol in hepatoma cells by increasing LDL receptor levels. (R)-IMPP apparently impairs PCSK9 secretion by causing transcript-dependent inhibition of PCSK9 translation.