Cold sores, also known as fever blisters, can be unsightly and uncomfortable. There are prescription antivirals like acyclovir or valacyclovir that may help speed healing. Many of our readers also report success with the amino acid L-lysine.
Q. I have taken L-lysine for years to prevent cold sores. I still get them off and on but they are tiny and nobody else notices them. They last only a few days compared to weeks.
I finally got my husband to use L-lysine too, and he hasn’t had a cold sore since he started taking it.
A. Many people agree with you that taking L-lysine tablets can help prevent cold sores or may speed healing. We have heard from hundreds of readers that this amino acid makes a huge difference in their lives.
Readers Re: L-lysine Remedy for Cold Sores:
Janet is fairly typical of many case reports:
“I have suffered with cold sores since I was a child. As an adult, I worked in several hospitals, and the chief pharmacist in one suggested all the possibilities he had heard that could help.
“It wasn’t until several years later that I heard/read about the L-Lysine remedy for cold sores. I bought it and tried it. What a blessing!
“At the first tingle I take 1000 mg in the morning and another dose before bed. The blisters never even form!
“I’ve been caught by surprise when traveling, and by the time I could get to a drugstore the blisters had all formed. By starting out doubling the dose the first day and then dropping back to the 1000 mg level after that, the blisters actually go back down — no sores/scabs.
“Now I’ve found the 500 mg capsules that are easier to swallow, and still work as well. Thank heavens for L-Lysine. I have also heard of several physicians who knew about L-lysine and recommended it to patients with shingles to help reduce the pain and length of the outbreak.”
Caz in Bristol, England:
“I have had trouble all my adult life with cold sores. Different areas of my lips were prone to flare up every few months and then take weeks to heal.
“I have been taking one L-Lysine 1000mg capsule each day for 9 months now. The results have been amazing. In that 9 months I’ve had only one tiny cold sore that took approx 4 days to heal. As soon as I felt the tingling of that cold sore I took one extra tablet for 3 days then back to one. I would recommend the L-Lysine remedy for cold sores to anyone to try.”
Nat offers this story:
“I used to get cold sores at least once every 2 months. And when I would have an outbreak, there would not be just one, but a whole CLUSTER of them in the same spot. So embarrassing and painful.
“I heard of L-Lysine and have been taking them. I don’t take it every day…only as and when needed.
“If I look closely in the mirror and see a slight colour change or texture change on my lips I would take a 500mg tablet before bed or whenever I noticed it.
“When you feel like one is coming on I would up the dose to 1000 mg. DOES THE TRICK! I am not joking.
“Two days ago I woke up with the tell tale bubble on the lip, put ice in a sandwich bag and held the ice on my lip for 3 minutes (it helps to reduce the newly forming cold sore under the skin) then douse it with acyclovir cream.”
Researchers Say Science is Lacking:
Unfortunately, there is very little research on this topic. A recent Cochrane review “failed to find any evidence of efficacy for lysine…” (Cochrane Database of Systematic Reviews, Aug. 7, 2015).
One bright spot: the reviewers also failed to find reports of adverse reactions to this supplement.
What has been your experience. Is the L-Lysine remedy for Cold Sores a bust or a boon? Please share your story in the comment section.
If you would like to learn more about other remedies for cold sores, check our our book, Quick & Handy Home Remedies.