The chemical Valacyclovir hydrochloride has a designated molecular formula of C13H21ClN6O4 and a molecular weight of 360.799 g/mol. Synonyms may include: Valtrex, BW-256U87, 256U87 hydrochloride, Valaciclovir hydrochloride, Valacyclovir, Valacyclovir HCl, UNII-G447S0T1VC, Zelitrex, BW 256 (ChemID). Valacyclovir hydrochloride has been assigned a MeSH pharmacological action of: Antivirals.