I've been taking a distinct lysine product (a thousand mg day by day). I do know that I've not had a cold sore since taking these. Additionally if you're having an outbreak then be conscious of the L-Arginine to L-Lysine ratio in your food plan you'll be able to look online for charts with the ratio of L-Lysine to L-Arginine in several meals. That is THE ONLY lysine product I exploit regularly