Used in the treatment of chronic hepatitis C virus (HCV) infection, particularly genotypes 1, 2, 3, and 4. It is a key component of direct-acting antiviral regimens, often combined with other antivirals like velpatasvir or ledipasvir. Works by inhibiting the NS5B RNA-dependent RNA polymerase, essential for viral replication. Highly effective, leading to high cure rates with shorter treatment durations and fewer side effects compared to older therapies. Commonly prescribed in both cirrhotic and non-cirrhotic patients, including those with HIV co-infection.