Every gram of Zovirax cream contains 50 mg of acyclovir as well as the inactive ingredients which include cetostearyl alcohol, mineral oil, poloxamer 407, propylene glycol, sodium lauryl sulfate, water, and white petrolatum. Fact Table Formula C8H11N5O3 License US FDA Bioavailability 15-20% Legal status US: RX Only Chemical Name Acyclovir Elimination half-life 2-4 hours Dosage (Strength) 5% (2 or 4 grams) Pregnancy Consult a doctor Brands Zovirax Cream Protein binding 9-33% PubChem CID 2022 MedlinePlus a681045 ChEBI 2453 ATC code J05AB01, D06BB03, S01AD03, D06BB53 DrugBank DB00787 KEGG D00222, C06810 Routes of administration Topical