Acyclovir is used to treat infections caused by certain types of viruses. It treats cold sores around the mouth (caused by herpes simplex), shingles (caused by herpes zoster), and chickenpox.
This medication may cause mild, temporary burning or stinging when you apply it. If either of these effects persists or worsens, tell your doctor or pharmacist promptly.
Before using it, tell your doctor or pharmacist if you are allergic to it; or to valacyclovir; or if you have any other allergies. This product may contain inactive ingredients (such as polyethylene glycol), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.