Can you reactivate a cold sore by using lipstick, on the 11th day of the healing process where the skin was already flaking?

No: Lipstick never reactivates cold sores. Inflammation involving thymidine kinase triggers replication of the virus with recurrent symptoms. This may be a fever, friction, sunburn, others. Oral valacyclovir and acyclovir are very effective if used at prodrome [onset of symptoms].

No: Oral herpes outbreaks generally do not recur so soon; few people have more than 3-4 outbreaks a year, usually fewer. Lipstick is not likely to reactivate an outbreak.