I believe that Brooke is referring to L-lysine which is an amino acid, not a vitamin. There is some anecdotal evidence that in the treatment of cold sores (herpes simplex) that it MAY reduce the time it takes for them to resolve. They normally have a 10-day life span. Health food stores and magazines have been touting lysine for this application for a long time, but the results have never been reproduced in peer-reviewed studies. It won't hurt anything to try it, as it is a naturally occurring amino acid that you get through your diet.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.