Lysine is an amino acid commonly taken as a dietary supplement. Taking one to three grams of lysine per day orally may help reduce herpes outbreaks such as cold sores, according to the University of Maryland Medical Center. Lysine paste is a common home remedy used to treat active cold sore outbreaks. Clinical data showing the effectiveness of topical lysine paste are lacking. Consult your doctor before using lysine paste.
Purchase a high-quality lysine powder from your local health food store. Make sure that lysine is the only ingredient, that it is 100 percent pure and listed as pharmaceutical grade. Lysine powder is relatively inexpensive. At the time of publication, you could find a high-quality lysine powder for about $10. Talk to your doctor to determine the amount that's right for you. Some people mix a single batch each day, while other people choose to mix the entire contents of the lysine bottle.
Scoop the lysine powder into your mixing container. If you are choosing to mix a single batch, then use about one teaspoon of lysine powder. To get a paste-like consistency, add a two to one ratio of water. In this case you will add two teaspoons of water. Stir the mixture until you reach a thick, paste-like consistency.
Lysine paste is most commonly applied at bedtime with a cotton swab. You can apply it on and around your cold sore. Proponents claim that doing so reduces the length and severity of the outbreak. Keep in mind that the University of Maryland Medical Center only mentions the possible benefits of oral supplementation.