The application segmentation of the Brivudine market is organized around three therapeutic categories: herpes zoster, herpes simplex, and other viral infections. Herpes zoster represents the dominant application, capturing approximately 70 % of market volume due to its FDA‑approved indication, extensive clinical evidence, and inclusion in national immunization‑treatment pathways. The herpes simplex segment, accounting for about 20 % of sales, reflects off‑label utilization in recurrent genital and oral lesions, where Brivudine’s pharmacokinetic profile offers a shorter treatment course compared with acyclovir. The residual 10 % comprises investigational uses such as cytomegalovirus prophylaxis and rare dermatologic viruses, which currently contribute modest revenue but signal potential expansion. By quantifying each application’s share, the Brivudine segmentation framework reveals that the herpes zoster cohort drives the bulk of the market size, while the smaller segments provide growth levers through clinical‑trial pipelines and regional prescribing variations. Consequently, strategic investment in the herpes simplex and investigational pipelines could diversify revenue streams and mitigate reliance on the primary indication.