anticholinergic drugs, dementia, Alzheimer's, cognitive decline, preventing dementia, deterioration from Alzheimer disease, prevent Alzheimer disease

Intriguing research suggests that the dementia we call Alzheimer’s disease may be triggered by a common infection: herpes virus. Although the story is not yet complete, the brain’s immune response to the viral intruder may initiate the development of amyloid beta plaques and tau tangles that are so distinctive. Yet there are hints that antiviral drugs might prevent Alzheimer disease. Could a simple supplement, L-lysine, also help?

Could L-Lysine Prevent Alzheimer Disease?

Q. Whenever I feel a cold sore coming on (the telltale “tingly feeling”), I take L-lysine tablets. When I take 1000 mg a day, often the cold sore will never develop. If it got a head start, it disappears several days sooner than it would otherwise.

I read your article about herpes and cold sores being linked to Alzheimer’s disease. Is there anything in L-lysine that could be helpful in preventing dementia? I’m going to start taking it every day, maybe 500 mg a day.

No Good Studies of L-Lysine to Prevent Alzheimer Disease:

A. There are few well-controlled long-term studies of the amino acid L-lysine to prevent or treat cold sores (HSV-1 or herpes labialis). A review in the dermatology journal Cutis (July, 2005)  concluded that L-lysine benefits against HSV-1 are unclear. It might help prevent recurrences in selected patients. That said, many readers report success like yours.

There is growing evidence to suggest a link between herpes infection and the risk of developing Alzheimer’s disease (Frontiers in Genetics, Sep. 10, 2018).  A study from Taiwan found that people taking antiviral medicines for herpes were significantly less likely to develop dementia (Neurotherapeutics, April, 2018).

Whether L-lysine would be beneficial remains to be determined. There is, however, some very technical modeling that suggests key lysine residues may help the brain clear itself of certain toxic metabolites (Interdisciplinary Sciences, Computational Life Sciences, Sep. 7, 2018). We’ll be watching for further research to see whether this translates into an ability for L-lysine supplements to prevent Alzheimer disease.

Get The Graedons' Favorite Home Remedies Health Guide for FREE

Join our daily email newsletter with breaking health news, prescription drug information, home remedies AND you'll get a copy of our brand new full-length health guide — for FREE!

  1. Alice

    I have had most of the herpes illnesses; chicken pox, mono, shingles, and I struggle with sores in my mouth regularly. My silver bullet for these is oil of oregano full strength as soon as I feel it coming. Works pretty well. Could this antiviral work the same as antiviral meds in possibly combating amyloid? Interested in your thoughts.

  2. Dennis
    Union, NJ

    It certainly cannot hurt at all, as I currently take 3 grams of L-Lysine and 1 gram of L-Proline along with Vitamin C 3 grams(as documented by Dr. Linus Pauling and Dr. Mathias Rath) along with Curcumin and Tart Cherry powder for both of its powerful antioxidant and bioflavonoids potent anti-inflammatory agent actions; now the Curcumin and Tart Cherry powder also act to enhance Vitamin C bioavailability absorption by ones body; all of the above primary and secondary ingredients listed above work also as potent atherosclerosis anti-inflammatory calming agents to help improve ones primary and secondary high blood pressure conditions and also effectively to teflon coat ones arteries to prevent further deposition of further potential future atherosclerotic deposits from building up.

  3. Joyce
    NN Virginia

    It may be a long wait for any definitive, meaningful research on the effect of L-LYSINE on Alzheimer disease. There is no money to made on L-lysine. It is very cheap and available. It was very effective for me in preventing cold sores for years. I will go back to taking 500mg daily. At 85 I do not have time to wait for research results. Forgetting words is very annoying ! The government needs to finance this research. If it works it will be a real money saver.

  4. Carl

    The best way I have found to stop a cold sore outbreak in it’s tracks is to apply a hot wash cloth as soon as I feel it coming on, as hot as I can stand for several minutes. Since herpes is a virus, and heat kills viruses, Voila!

  5. Kay

    I’m an active 79 year old and have been taking Lysine for 30+ years. It has kept my herpes under control. If I feel the tingly prebreakout sensation I double up on dosage ASAP. It works.

    My concerns now are for Alzheimer’s and dementia. My mind has slowed down. My recall isn’t what it once was. If I’m anxious or stressed recall is a blank slate. When I relax and let go sometimes the words or ideas come back.

    I now have medications I use sparingly to help me sleep or for anxiety. 50 mg Trazodone, an antidepressant helps with sleep. 5 mg Diazepam for particularly anxious situations. I cut both in half and am reluctant to use, I’m concerned they may make my fading memory worse. Would appreciate feed back.

  6. Charlie

    Any bad side effects from taking 500 mg L-lysine daily? It sure works on my cold sores, and I’m not averse to supplements, but I’d like to know if trying it is asking for trouble.

    • Carol

      Charlie, I don’t know if there are any bad side effects from taking 500 mg L-Lysine daily, but I’ve been taking it about 6 months and don’t seem to have any side effects. Think I’ll google it.

    • MollyK

      I’ve been using l-lysine for years, to prevent mouth sores after any dental work. My dentist recommended it and said I could not overdose on it. I now take 500 mg twice a day along with 500 mg. of vitamin C. I have not been sick or had a cold sore in years.

  7. ANNE

    I need to get more L-Lysine. I was taking it daily until I recently ran out. I also make I have plenty of refills for Valtrex available. In fact, I try to have a prescription on hand so I can take it ASAP!

  8. Hatty

    I had shingles about a decade back. When I start feeling the itch on my torso, I start Lysine 1000 3 times day, and after few days the itch was gone, no shingles. I have herpes and fibromyalgia. I have read they are related. I was taking Lysine for fibro symptoms as well. Then read I maybe should not be taking daily.

    • Carol Kroll

      Hattie, your control of shingles is amazing. Thanks for the tip!

  9. Andrea K.

    I am 78 years old. My Grandmother was born in 1873. In the early 1900’s she patented a cough syrup. She was very wise, and I tell you this to tell you what she always told us to do when we felt a fever blister coming on. She told us to rub our finger behind our ear lobe, and then rub our finger on the beginning fever blister site. I do this several times a day when I feel one coming on. I know this may sound crazy but it has always worked for me.

  10. Harvey

    There are those who claim a ketotonic diet, which induces autophagy, reduces inflammation in the brain and removes amyloid plaques from the brain. They claim this helps Alzheimers. Does anyone have actual experience with this?

    • MR

      I don’t know about autophagy and the ketogenic diet, but have had this experience: 9 months ago I felt that I was having too many “senior moments”. I went on a grain-free and gluten-free diet, have felt more mentally clear, and intend to stay on this diet for the foreseeable future. I have read that healthy carbs are important for metabolism, and feel that all the fresh fruit, sweet potatoes, winter squash, etc. in my diet are good for me. The fish oil and exercise don’t hurt either.

What Do You Think?

We invite you to share your thoughts with others, but remember that our comment section is a public forum. Please do not use your full first and last name if you want to keep details of your medical history anonymous. A first name and last initial or a pseudonym is acceptable. Advice from other commenters on this website is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. Stopping medication suddenly could result in serious harm. We expect comments to be civil in tone and language. By commenting, you agree to abide by our commenting policy and website terms & conditions. Comments that do not follow these policies will not be posted. Learn how your comment data is processed.

Your cart

Shipping and discount codes are added at checkout.