The over-the-counter cold sore ointment docosanol (Abreva) may shorten the healing time of a cold sore. At the first sign of symptoms, apply it to the affected skin as directed on the package. Use a cotton-tipped swab to put medicine on a cold sore. This helps prevent the spread of the sores to other parts of your body.
https://www.mayoclinic.org/diseases-conditions/cold-sore/diagnosis-treatment/drc-20371023