What Lipitor Does to HMG-CoA Reductase
Lipitor (atorvastatin) binds to HMG-CoA reductase, the enzyme that controls the first major step in cholesterol production in the liver. It acts like a fake version of the substrate HMG-CoA, locking into the enzyme's active site and stopping it from converting HMG-CoA into mevalonate—the precursor for cholesterol synthesis.[1]
How This Lowers Cholesterol
By blocking about 90-95% of the enzyme's activity at full doses, Lipitor slashes liver cholesterol output by up to 50%, prompting the liver to pull more LDL cholesterol from the blood via upregulated LDL receptors.1
Why Patients Take It
Doctors prescribe it to cut heart attack and stroke risk in people with high cholesterol; it reduces LDL by 40-60% depending on dose (10-80 mg daily).2
Common Side Effects Linked to This Action
Muscle pain (myalgia) affects 5-10% of users, tied to low mevalonate levels disrupting muscle cell function; rare rhabdomyolysis can occur.2
[1]: https://www.ncbi.nlm.nih.gov/books/NBK430940/