Key takeaways
Docosanol (Abreva) and valacyclovir (Valtrex) are both antiviral medications used to treat cold sores, but they have some key differences. Docosanol is a topical cream that you apply to the face or lips at the first sign of a cold sore, and it is available over the counter. In contrast, valacyclovir is an oral medication that requires a prescription and can treat a wider range of infections, including genital herpes, shingles, and chickenpox. Docosanol works by preventing the herpes simplex virus from entering healthy cells, while valacyclovir is converted into acyclovir in the body and stops the virus from making copies of itself. You need to apply docosanol five times a day until healed, whereas valacyclovir is typically taken twice daily for one day for cold sores. Valacyclovir can cause side effects like headaches and nausea, while docosanol might cause mild stinging at the application site.
