Compeed Invisible Cold Sore Patches (15). You can use the cold sore patch at any stage of an outbreak. However, it is best to apply at the first sign of an an outbreak – usually a tingling or itching sensation.. Wash your hands before and after applying the COMPEED® Invisible Cold Sore Patch.. COMPEED® Invisible Cold Sore Patch should be used 24 hours a day until the sore is healed*. A patch will naturally detach after approximately 8 hours and should then be replaced with a new one.. Don’t remove the patch because you want the sore to ‘breathe’. This is actually counter-productive and can lengthen the healing process. Keeping the patch on is clinically proven to ensure the optimal healing environment is maintained.