Napguard is used to prevent sunburn. It is applied on the affected area as advised by the doctor. Napguard 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. This is usually a safe medicine, however, it may cause increased skin redness, irritation or rashes as its side effects. Please consult your doctor if these side effects persist for a longer duration.