Used in biochemical research as a nucleotide analog prodrug, particularly for the treatment and study of chronic Hepatitis C virus (HCV) infection. It enhances cellular uptake, especially in hepatocytes, and is metabolized to its active triphosphate form that inhibits the HCV NS5B RNA-dependent RNA polymerase, preventing viral RNA replication. Serves as a key intermediate in synthesizing modified nucleotides mimicking natural substrates to probe kinase and polymerase mechanisms. Its structure enables incorporation into nucleic acid chains, aiding investigations of RNA and DNA metabolism. Integral to interferon-free antiviral regimens, improving cure rates and reducing side effects when combined with other direct-acting antivirals.