Q. I have always suffered from terrible cold sores as far back as I can remember. I am especially vulnerable in the summer when I spend a lot of time outdoors. Even with lip balm that has a sunblock I am frequently in pain.
These sores are incredibly ugly and people always stare. That makes me even more self-conscious about them. What can you recommend to prevent cold sores or speed healing once they occur? I have heard that lysine might be good but I know nothing about this stuff. What is it and how well does it work?

A. Cold sores, also called fever blisters, can be painful and look yucky. Some people have outbreaks once or twice a year. Others seem to have recurrent lesions every few weeks. Once our bodies are infected with this herpes virus it remains forever. Why some people are more vulnerable to attacks than others remains mysterious. Clearly our immune systems play an important role in this process. Sun exposure can bring on an outbreak. So can a trip to the dentist (presumably because of mild trauma associated with such procedures).
Although we are enthusiastic about lysine (more about this supplement in a minute) we would be remiss if we did not mention that there are effective anti-viral agents for type 1 (HSV-1) herpes infections that cause cold sores. Zovirax (acyclovir) and Denavir (penciclovir) are available in cream form. Your doctor could alsp prescribe oral anti-virals as Famvir (famciclovir), Valtrex (valacyclovir), and Zovirax.
If you prefer a more natural and affordable approach, you may want to seriously consider lysine. The arginine/lysine theory of cold sore management remains somewhat controversial within the medical community. It goes something like this. The amino acid arginine is essential for herpes viruses to replicate and multiply. Arginine is high in nuts (such as almonds, Brazil nuts, peanuts, walnuts, etc), pumpkin and squash seeds, sesame seeds, red meat and some cereals (oatmeal for example). People are advised to cut back on high arginine-containing foods and add lysine supplements to their regimen (1000 to 1500 mg total daily dose). Lysine is supposed to make it harder for the herpes virus to replicate.
We were somewhat skeptical of this approach as there were been both negative as well as positive studies with lysine. Most of the research was with small numbers of patients and seemed inconclusive to us. Nevertheless, some of the double-blind, placebo-controlled trials lasted from 12 to 52 weeks and reported significant reductions in cold sore outbreaks among the lysine groups.
What has convinced us that something positive was happening with lysine has been the outpouring of letters from dental professionals and our readers. We have received so many anecdotal reports of success that we are convinced something is going on here We share just some of the lysine success stories with you:
One oral surgeon wrote to say his patients do well on a preventive regimen of one 500 mg tablet of l-lysine daily. If they develop a sore, increasing to four tablets a day seems to help it heal faster. A reader said, “I suffered from cold sores since I was a little boy and my doctor prescribed acyclovir, which wasn’t any help. My pharmacist suggested lysine, and I have been taking 500 mg of this amino acid for two years now. I am free of fever blisters and that’s a great relief.”
Q. When you wrote recently about home remedies for cold sores, why in heavens name didn’t you tell peple about l-lysine?
For 50 years I would develop fever blisters every time I went out in the sun. About 4 years ago a pharmacist told me about l-lysine. Since then I have taken it for a week before I know I’ll be exposed to sunshine. I have not had a cold sore since.

A. We were flooded with letters like yours praising the power of l-lysine. One young woman writes, “my boyfriend got these sores constantly, and as a last resort we went to the health food store to see if there was anything that could help. He was told to take lysine and the sores have never returned.”
Another reader reports suffering from nasty fever blisters that lasted 3 or 4 weeks. She was told by a friend to take lysine, and when she was skeptical the friend said, “then live with them if you’re stubborn.”
She now takes l-lysine whenever she feels a cold sore coming on or if she is in the sun more than usual. She says, “it quickly nips them in the bud. Doctors and druggists don’t seem to believe this, but I know it works.”
Judging from our mail bag, l-lysine does help many people. Though it may not work for everyone, this amino acid may be worth a try.
We would love to hear your story (positive or negative). Share your experience with l-lysine below in the comment section.

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  1. Graham

    Anyone heard of http://www.balancednutbutters.com? Nut butters with added lysine and other stuff. I’ve been avoiding nuts for years, but love peanut butter. Wondering if anyone has tried their products?

  2. Stephanie

    Hi guys,
    I use to get cold sores all the time. It was horrible. At one point I was getting one about every 4-6 weeks. I’ve tried everything under the sun to avoid, prevent, lessen, and cure the little buggers. Including most of the remedies below. Nothing ever worked. Occasionally I’d have success with prescription meds, or l-lysine supplements. But it would would work once and then the next time would be ineffective. Anyhow, about a year ago i really took a look at my diet. I didn’t have as many outbreaks when i was very young. Maybe once or twice a year. The only food that I could think of that I was consuming more of as an adult was dairy. I consumed a lot of milk, yogurt, and cheese etc since moving away from home and living on my own.

    I never thought in a million years that dramatically reducing my intake of those foods would help. But it has. Last year i virtually eliminated milk and yogurt from my diet. I don’t want to temp the gods, but i haven’t had an outbreak in over 6 months. For me, that’s a small miracle. Nothing else in my life, food, job, relationship, exercise, stress, sunlight, etc etc has changed. I just find it strange that many home remedies, if you want to call it that, recommend a diet rich in the amino acid l-Lysine which means lots of dairy. I’ve gone the opposite, and I still enjoy chocolate, nuts, whole wheat bread etc type foods (low in l-lysine) without any troubles. Just wondering if anyone else has experienced lower outbreaks after cutting milk from their diets?

  3. Russ 88

    What worked for me was applying a paste made of pressed garlic. I only leave it on the lip for a few minutes, because it really starts to sting after 30 seconds, or so. I suspect only one application will do the job, but I really want to ward off the cold sore, so I do about six applications, more or less. Applying the garlic as soon as I get the tingle, works the best. Garlic paste seems to pretty much stop the herpes virus in its tracks.

  4. brigitte
    United States

    My daughter gets them constantly. I have tried everything and read once real vanilla extract worked well. She started with one and I thought i’d try. It works just as well and quickly as the other stuff we had tried, plus it tastes good. I dab it on many times in a day. I also read to soak a cottonball in milk and press it on the sore often, we do this too. I no longer buy any of the creams as I have found this to be equally as effective and costs much less!

  5. Kat

    I’ve suffered from cold sores all my life. They come out when I’m run down/sick or experiencing high levels of stress. I use lysine and Zovirax and a little something extra that is the nail in the coffin for my cold sores. The moment I get the tingling sensation or the beginning of a lump, I put an ice pack on it and I’ll do this a couple times a day, especially after a hot shower. After making the little devil numb, I put on the Zovirax. Along with taking two lysine in the morning and two at night during an outbreak, I can cut the healing time down to 1-3 days, depending on how quickly I can get to the outbreak. Back when I was only using Zovirax, healing time was 2.5 weeks.

  6. bn

    cpmt, what vitamins and herbs are you taking?
    My first outbreak was about 2 and a half years ago, and I’ve only had a few cold sores each year and they are mild, but this year I have had continual trouble with red spots coming up without tingling or warning. they do not turn into blisters, but they are still annoying. I don’t know what to do. I use lysine, hl30, oils, and take some other vitamins to help my immune system. also valacyclovir. I have been dealing with the red spots (that I believe can still be contagious) for too long. It’s taking a toll on me. I know I am lucky that they aren’t worse, but I fear I can’t be close with anyone or kiss as I might transmit it to them. Also, it has prevented me from eating lots of foods I used to because anything remotely spicy causes a red spot, as well as other food. Does anyone have the same problem? This has become a daily disturbance and I can’t figure out what to do besides stop eating, like I want to.

  7. cpmt

    TO DJM In my opinion YOU SHOULD stop everything you are taking. you’re probably allergic to something, also check if you are allergic to gluten or lactose etc…
    your immune system is low or damage probably from all the things/meds you are taking. Something similar happened to me. Doctor prescribed 5 medicines to stop ONE illness… I got so sick I ended in the ER I guess I am allergic to some of the medication OR one medicine doesn’t go with another.
    I feel better now that I stopped everything. I went to an acupuncturist (who is treating me) and she gave me a special formula vitamins + herbs to improve my immune system. I am feeling better and the original illness is very much improving. Good luck.

  8. DJM

    I have been plagued by cold sores for 20 years. I take 1000mg l lysine everyday, I take a 200mg maintenance dose of Zovirax everyday. I use 50 SPF lip balm every second I am in the sun. I have been suffering since the first of June 2014 with outbreak after outbreak. When they break out I use 2 grams of valacyclovir every 12 hours for two days, two tubes of those newer Oragel vials, and almost an entire tube of Abreva every outbreak along with every single hint from Heloise I can find but they keep coming back.
    What the heck is going on with me? I don’t even get a sting or a pulsing anymore, they just show up like the unwanted guests they are.
    This crap is costing me a fortune and short of cutting my upper lip off, I am at the end of my rope. Any help or hope other than the slew of information those of us that suffer from them already know? I feel it is stupid there is no cure for this….. Come on science, how about a cure for something that afflicts millions of people instead of all the focus going to just a few.

  9. dlw

    I just purchased some 1000mg L Lysine. Does it really work?

  10. MS

    Aside from prevention methods such as avoiding stress and fatigue, as well as exercising and eating appropriately (getting all your vitamins, proteins, upping lysine intake and avoiding arginine-rich foods), there is a winning formula of 4 treatments that will fight any outbreak (provided you catch it in time). When you feel the dreaded tingle:
    -Take 3 L-Lysine supplement pills daily (can be found at any GNC)
    -Take 2 Valacyclovir pills every 12 hours for 2 days (need a prescription from your Dr.)
    -Put Zovirax cream on the sore every 3 hours
    -Put Abreva cream at the same time as Zovirax (mix both together and apply generously)
    Until they find a cure, this is your best bet. Has been working for me for 8 years (since I started it).
    Good luck!

  11. PI

    Thanks for sharing all the tips everyone. I’ve been getting coldsores since I was kid and as I get older they get worse. The past few months I’ve had one every few weeks. I’m going to get some Lysine asap and take it daily. Have the icepack on now.

  12. js

    I too am a firm believer in L-Lysine, at the very first tingle I will take anywhere from 2-5 1000mg pills, if I know I will have lots of sun exposure, or that I am stressed out, or run down, I will take a couple in the morning and a couple before sleep; preemptively. I keep lysine in my glove box, in my day bag, golf bag, gym bag, and at home. I literally will not go anywhere without it, so that I can take it immediately if i feel a cold sore coming on, or if I am consciously stressed, tired, sick, etc. I also have learned to avoid caffeine, chocolate, most nuts, and other foods that are rich in L-Arginine. There are tons of articles explaining how food and diet can assist in preventing and limiting the extent of breakouts. With this current approach, I usually do not get any sores that are visible, and am able to keep them in check..

  13. Sharon

    My dentist told me many years ago to use Lysine as soon my lip starts to sting. I take three Lysine immediately and the sore will not go on and develop. The second and third days, I take three more. No blisters for me.

  14. MB

    Did you get any help? As I seem to get one after another and nothing helps it. My self esteem is shot. :(

  15. Johnnie J.

    2 years ago I started putting extra virgin cold pressed coconut oil on and all around the area when I feel the tingle, it prevented the cold sore. If I miss the tingle and end up with the Beginnings of a cold sore I put some on and it heals very fast.

  16. Sfitz

    I take 3,000 mg of lysine every day and still get them.
    Doesn’t work for everyone unfortunately.

  17. Gem

    I have suffered with cold sores all my life and have found that the only thing that helps is tea tree oil and aciclovir 400mg tablets which can also be used as a preventor. The pills are given to people whose immune system is weakened by having chemo or radiation therapy and people who suffer bad breakouts frequently.
    I also find if I take care of my lips during winter and summer with Blistex that I’m far less likely to have an outbreak. If you have a bad breakout I found that the treatments via your gp for impetigo (which is bacterial) also work.

  18. cpmt

    ah, I forgot to mention, stop eating gluten – flour – for a few weeks, and then do the same with milk products for a few weeks and see if that helps. Some people are sensitive to gluten and/or lactose /casein etc… and have different reactions.

  19. cpmt

    TO LEW I think you should check out if you are lacking some lack of a mineral, vitamin or enzyme or … something your body is not assimilating well. When this happens in a family is because genetics and something is missing. Try to boost your immune system with superfoods. Also, it is possible you are allergic to something/or food. I get blisters in my mouth and lips when I eat fresh pineapple (which I love).

  20. Lew

    Wow, interesting forum. I haven’t read an experience quite like mine though – I had the herpes first when I was 6 months – throughout my mouth and down my throat – nasty. I’m from Swedish stock and all the Swedes in my family get’em. I always got them every so often on my lips only when I was stressed or sick. I met my husband during veterinary school and I believe he carries a wicked strain of which he is asymptomatic.
    Ever since the first kiss I started with an evil bloom on my bottom lip and now will get them not only on my lips but now sores IN my mouth – on the roof, on my gums, inside of lips even UP MY NOSE! GAHH! Lysine doesn’t work, Valtrex did for awhile but now doesn’t work anymore. I think now I have to change my diet to shortcut arginine – don’t know what else to do.
    My husband makes fun of me when I have food on my lips. Well, I think so many cold sores for so many years has led to friggin nerve damage. I have to be really careful with my kids. I think this virus wants them too, argh.

  21. cpmt

    The cure with urine is a very old remedy used in the orient China, India etc… used for many skin problems like eczemas, ..toenail & athlete’s foot etc.

  22. Grampi

    As I have put in here before: When I was young, an old farmer, believe he was part American Indian, told me to put a dab of my own urine on it! Works 100% every time!

  23. cpmt

    Sauerkraut and the juice can help.

  24. Diane

    Ok, I’ve been getting coldsores for about 20 years, and like all of you I HATE THEM! I’ve tried alcohol, abreva, silver, camphor, and even zapping it with a 9-v battery! Nothing seemed to help once I had one and would have a hideous scabby, oozy, swelled up lip for about a week… I have had some relief with Lysine, if I catch it fast enough! But now when one sneaks up on me (sometimes I wake up to one) I apply frankincense essential oil several times a day and it heals it so quickly! I don’t have any oozing or scabbing, or swelling. It seems to dry it up. Within a few days it’s gone! Thank goodness! Hope this helps….(I also continue to take Lysine along with it, but I have noticed a remarkable improvement with the Frankincense)

  25. Tammy

    Be careful with the Lysine. I had been taking them for about 6 months and my back started hurting. I thought I had hurt it somehow. I have pulled it our before. I hurt so bad I could not get out of bed for a week. Finally, after starting to get a fever…I knew back aches did not cause fevers…
    I went to the Dr. Turns out my kidneys were about to shut down. I had to take 2 rounds of antibiotics and it still took several weeks to get over it. I, not realizing it was the Lysine causing this, continued to take it. A month later I was back at the Dr. with the same problem. I knew it had to be something I was taking and the only thing different was the Lysine. I stopped it immediately and haven’t had any more problems with my kidneys. It’s been over 2 years! Just be careful. A fever blister is better than kidney damage.

  26. Grampi

    I replied to this a long time ago. But, perhaps, it is, seemingly, to gross for most people. Many years ago, an old farmer told me that is you dab a bit of your own urine on the cold sore, it will be gone in 24 hours! It has always worked for me, & for a few others who have tried it.

  27. laura

    I have also used lysene to no avail! I have found the only thing that works is geranium oil placed on the skin as soon as I feel a tingle. If you catch it in time in works.

  28. Stephanie

    Hi, I’ve been getting cold sores all of my life. This may sound a bit odd, but I put plain white toothpaste on them at night to dry them out. Then during the day… As soon as I get a tingle I put and hold rubbing alcohol swabs on it. It dries it right up and my blisters no longer spread. It does dry out my lips of purse but I’d rather have chapped lips than a cold sore any day.
    I’ve found that although all my doctors said to keep the area moist, my blisters would continue to spread for weeks! And I’ve tried the lysene and it just didn’t work. Now from the time I get the first tingle to the time it dries out and stops spreading is only a day or two and they don’t get nearly as large as they use too. So like I said, I put alcohol swabs on the area as soon as I feel one coming, and then at night I put white plain toothpaste on the area. I know it’s really weird but I swear by it!!!

  29. Trudy

    I have had fever blisters all my life- the secret I have found that finally works for me is bitter melon in capsule form. It’s worth trying- but you have to take more than it says to take- I would try taking several throughout the day every couple of hours the day you get it. This works for me…. used to just get bigger and bigger even with lysine- now it doesn’t even fully form if I hit it right away with bitter melon and intermittently throughout the day. Hope this helps someone:)

  30. Erin

    Thank you everybody on here for your helpful suggestions. I have been getting cold sores on and off since about the age of five. I am now into menopause and that seems to have made them come back with a vengeance! I do appreciate being told to keep away from nuts and oatmeal, etc. And will definitely be using the ice pack thing. I find that taking Lysine everyday keeps them at bay (I run out and forgot to replace so have just recently suffered one again). I use Zovirax which seems to lessen them also. All the best to fellow sufferers, I wish ‘they’ would find a cure.

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