I've been taking a special lysine product (one thousand mg every day). Also for those who're having an outbreak then take heed to the L-Arginine to L-Lysine ratio in your diet you may look on-line for charts with the ratio of L-Lysine to L-Arginine in numerous foods. I do know that I've not had a cold sore since taking these. This is THE ONLY lysine product I use regularly