Back in the mid 80's my girlfriend at that time saw me breaking out on my upper lip. She instantly told me about Lysine and vitamin C.
I've been taking Lysine and vitamin C since then, and have stopped outbreaks about 70% of the time. When I do have an outbreak, usually on my upper lip, Lysine and vitamin C shorten the active period and make the healing much faster. I don't use any skin treatment as the herpes is causing the breakout from within the skin.
I've experimented over the years with taking only one or the other and they don't work nearly as well apart.
When I feel an outbreak coming on, I take 2000mg Lysine and 1000mg of chewable vitamin C with each meal. Works reliably and quickly for 25 years now.