Valtrex is an antiviral medication available in tablet form, containing the active ingredient Valacyclovir. It is indicated for the treatment of herpes virus infections, including herpes zoster (shingles), herpes labialis (cold sores), and herpes simplex in adults. Valtrex tablets are available in two strengths: 500 mg and 1000 mg. This medication is also marketed under the names Valcivir, Valkon, Valanix, Valtoval, and Zimivir.