Alirocumab (trade name Praluent) is a PCSK9 inhibitor used to treat elevated cholesterol, particularly in patients who need additional LDL lowering beyond statins or who cannot tolerate statins. It works by blocking the PCSK9 protein, which allows the liver to keep more LDL receptors on its surface, leading to greater clearance of LDL (“bad” cholesterol) from the bloodstream. Alirocumab is given as a subcutaneous injection every 2–4 weeks and can reduce LDL cholesterol by up to 60%. It is commonly prescribed for patients with familial hypercholesterolemia or established atherosclerotic cardiovascular disease to lower the risk of heart attack and stroke.