Ledipasvir is an antiviral medication used to treat chronic infections caused by the hepatitis C virus (HCV). It works by inhibiting a specific protein that the virus needs to replicate, helping to reduce the amount of virus in the body. Ledipasvir is often combined with another antiviral drug, sofosbuvir, to enhance its effectiveness. This medication is typically taken as a once-daily pill and is part of a treatment regimen that can last from 8 to 12 weeks, depending on the patient's condition. Common side effects may include fatigue, headache, and nausea, but many patients tolerate it well.