Cold sores can be painful and unsightly. They are caused by a virus (usually herpes simplex virus 1). Recurrent cold sores can be treated effectively with prescription antiviral medicines such as acyclovir (Zovirax), famciclovir (Famvir), or valacyclovir (Valtrex). Many people prefer a less expensive remedy, however.
A few weeks ago a reader wrote to you about cold sores. This person derided the use of “silly” remedies like lysine. I know from experience that lysine works, but plain old buttermilk works just as well and even more quickly.
Physicians, pharmacists, and housewives have all written to tell us that taking the amino acid lysine and drinking buttermilk both work to prevent cold sores (fever blisters) or canker sores (aphthous ulcers). There are no placebo-controlled trials, but this seems like an inexpensive and low-risk approach.
You had an article about drugs that heal cold sores faster. Why not prevent them? I take L-lysine before meals every day to prevent cold sores from developing into blisters. Prevention is better than cure.
Several studies suggest that the dietary supplement L-lysine may reduce cold sore outbreaks.1 The optimal dose is unknown, but side effects seem rare. Some people contend that limiting the amino acid arginine in the diet improves the effectiveness of L-lysine. Foods high in arginine include chocolate, nuts, and seeds.
I get cold sores and was told to take L-lysine daily to help prevent them. I take one pill per day and have not had a cold sore in five months! Is L-lysine dangerous?
L-lysine is an amino acid, a building block for protein. Several studies have shown that it prevents cold sores. It appears quite safe, except for people with kidney or liver disease.
Joe Graedon & Terry Graedon, The People’s Pharmacy: Quick & Handy Home Remedies, published by National Geographic