R-IMPP is a potent and selective inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9) secretion that stimulates uptake of LDL-C in hepatoma cells by increasing LDL-R levels, without altering levels of secreted transferrin. R-IMPP binds selectively to human ribosomes and causes transcript-dependent inhibition of PCSK9 translation.