Fenistil cold sore cream is proven to be effective when applied as early as possible at the first sign of a cold sore developing fenistil cold sore cream speeds up healing shortens the duration of pain shortens the time the cold sore is infectiouscontains penciclovir 1 apply to the affected area at approximately 2 hour intervals throughout the day for 4 days not suitable for children under 12 years of ageif symptoms persist consult your doctor do not use in eyesfor external use only ke