Dolichol is a product of the HMG-CoA reductase pathway (also known as the mevalonate pathway), and as such their creation and availability are affected by mevalonate inhibition. First, a cis (or Z) -prenyltransferase catalyzes the condensation of farnesyl diphosphate (FPP) with a varying number (dependent on the particular cis-prenyltransferase) of isopentenyl diphosphate (IPP) molecules, resulting in the formation of a polyprenyl diphosphate (also known as dehydrodolichyl diphosphate). This subsequently undergoes loss of both phosphate groups, resulting in a polyprenol (dehydrodolichol).