Key takeaways
Acyclovir (Zovirax) and docosanol (Abreva) are both antiviral medications used to treat cold sores, but they have some key differences. Acyclovir (Zovirax) is available in various forms, including oral pills, buccal tablets, and topical creams or ointments, and it requires a prescription. It treats a range of herpes virus infections, including genital herpes, shingles, and chickenpox. In contrast, docosanol (Abreva) is an over-the-counter cream specifically for cold sores on the face or lips. Acyclovir works by stopping the virus from making copies of itself, while docosanol prevents the virus from entering healthy cells. Acyclovir needs to be taken or applied multiple times a day, depending on the form, whereas docosanol is applied five times a day. Acyclovir can cause side effects like nausea and diarrhea, while docosanol's side effects are usually mild, such as stinging at the application site.
