Brivudine is a L-nucleoside analog of thymidine that exhibits antiviral, anticancer chemotherapeutic, and insecticidal activities. Brivudine inhibits herpes simplex virus (HSV-1) thymidine kinase, preventing DNA chain elongation and inhibiting viral growth. Brivudine also binds heat shock protein 27 (HSP27/HSPB1), improving the efficacy of co-administered chemotherapeutics in vivo and in clinical settings. This compound also exhibits properties of an insecticide, slowing larval growth and development of Spodoptera worms.