Abreva Cream is the only nonprescription cold sore medicine approved by the FDA to shorten getting rid of time. Its unique formulation uses the active ingredient Docosanol to penetrate deep. Abreva can help get rid of your cold sore in as little as 2½ days,* when used at the first sign. Cold sores, also known as fever blisters or oral herpes, are very common. They can be easy to recognize as they usually appear as red bumps or blisters around the lips and mouth.