[header] How to get rid of a cold sore with home remedies [title] Use hydrogen peroxide. [step] Hydrogen peroxide has antiseptic and antiviral properties that can help reduce inflammation and fight the viral infection causing the cold sore. [substeps] Soak a cotton ball or cotton swab in one teaspoon of hydrogen peroxide and hold it directly over the cold sore for five minutes. 
Rinse your face gently with cold water afterwards, and throw away the used cotton ball. Make sure not to ingest the hydrogen peroxide as you apply it.