Aciclovir 5% ointment is an antiviral medication primarily used to treat infections caused by herpes viruses, including herpes simplex and varicella-zoster. This topical ointment is applied directly to affected areas of the skin. The active ingredient, aciclovir, works by inhibiting the growth of the virus, thereby reducing symptoms such as pain, itching, and the formation of new lesions. It is advisable to apply the ointment several times a day for optimal results, as recommended by a healthcare professional. Proper hygiene measures should be followed when applying the ointment to prevent further spreading of the infection.