PCSK9-IN-30 (Compound 3f) is a PCSK9 inhibitor. PCSK9-IN-30 interacts with a cryptic binding groove of PCSK9 , inhibiting the binding of PCSK9 to the low-density lipoprotein receptor ( LDLR ) ( IC 50 = 537 nM), restoring the uptake of low-density lipoprotein (LDL) by liver cells, and ultimately reducing plasma cholesterol levels. PCSK9-IN-30 exhibits good bioavailability in mice and can be used for research in the field of cardiovascular diseases.