text: how do i prevent and treat coldsores?   wear chapstick with an spf to prevent them because the sun can make them pop up. also if you feel one coming, take an l-lysine pill (often, as much as the bottle says to take) this also can be taken to prevent them. and try using a product called "abreva" its kind of expensive ($17) but works great. the trick is to use it asap because it speeds up the healing process. if they become a big problem try seeing a doctor, my sister used to get them all the time, since she saw a doctor, she prescribed her a strong medication and now she never gets them.