Knock on wood ,never been bothered by acne. But cold sores are another thing, at least once a year. This really works...... when you feel the first tingle or warm spot on your lip... grab a q-tip or cottonball soaked in rubbing alcohol, yes rubbing alcohol!Apply every 30 mins. or as often as you can. Stops them if you catch it before it raises the skin, reduces the time if it has already bumped up your lip. Just be prepared to hold your nose , it also makes my eyes water.. but it is worth it.