Zoster Cream is an antiviral medicine which helps in treating skin infections caused by Herpes simplex virus such as herpes labialis. It prevents the multiplication of the virus in skin cells and therefore helps in clearing the skin infection. Zoster Cream is for external use only. You should use it in the dose and duration as advised by your doctor. The affected area should be clean and dry before application of the ointment. You must wash your hands thoroughly before and after applying this medicine. Do not touch the sores unnecessarily with your hands or towel, to avoid spreading the infection. Some common side effects include burning, irritation, itching and redness of the skin, at the site of application. Please consult your doctor if these side effects persist for a longer duration. Do not use it in the eyes, mouth, nose or vagina as it may cause irritation. If accidental exposure occurs, rinse immediately with plenty of water.