Lysine is considered a potential cold sore remedy is because it’s known to slow down the body’s production of arginine – another amino acid that helps the HSV virus to spread.i, iv But while some take this to mean that increasing your lysine intake will help to stave off a cold sore outbreak (or treat one that is already occurring), the research on this topic is still inconclusive. Despite several studies on the topic, experts have not been able to say for sure that lysine can prevent, treat or manage an outbreak of cold sores.v, vi To find out if lysine is right for you, consult your doctor.