<p>Valacyclovir is the hydrochloride salt of L-valyl ester of the antiviral drug acyclovir. Valacyclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Valacyclovir lessens the symptoms of infections and shortens the length of time of sickness. Valacyclovir is used in the treatment and suppression of genital herpes, shingles and cold sores.</p>