Valaciclovir disrupts the process by which the herpes virus family. Valtrex is an anti-viral drug that is believed to suppress the herpes virus. It is not known if Valtrex prevents the spread of the herpes virus reproduces itself and spreads to other cells in the body. It is believed that Valtrex reduces the chance of reoccurrence. Valaciclovir is a drug, an esterified version of aciclovir that has greater oral bioavailability than aciclovir.