Lysine may prevent cold sore outbreaks

Long before prescription medications became available to control herpes simplex outbreaks, which cause cold sores, lysine was considered a useful weapon to combat herpes infections. Many people still prefer the natural remedy over a newer prescription drug because of lysine’s safety and low cost. An amino acid, lysine is not produced in the body but can be found in high quantities in milk, soybeans, lentils and meat.

Uses: Primarily to prevent recurrences, and limit the severity, of cold sores. While the amino acid arginine, which is found in nuts and chocolate, promotes the growth of the herpes virus, lysine is thought to suppress the virus by increasing the ratio of lysine to arginine.

Dose: High doses of lysine, 1,000 to 3,000 milligrams per day, are typically taken for a short period of time to control a herpes outbreak.

Precautions: Taking high doses of lysine for long periods of time could be risky, and, thus, is not recommended. Lysine can cause mild stomach distress in some people taking high doses.

Research: The studies on lysine’s prevention of fever blisters have generally pointed to evidence of some benefit. Some studies also indicate lysine may help the body absorb calcium, but more research in humans is needed.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.