Foods to Avoid with Cold Sores - Arginine, lysine, and other diet strategies for cold sores

If you get recurring cold sores a couple times a year, every few months, or even every month, then you no doubt suspect that your diet has a part to play.

It’s true, there are certain foods to avoid with cold sores if you want that a-hole herpes virus to leave you alone for more than a minute.

What are those foods?

Well, according to most resources on foods to avoid with cold sores you’ll find online, it breaks down like this:

  • Avoid foods with arginine (like peanuts and chocolate)
  • Avoid acidic foods
  • Avoid processed foods, sugar and alcohol

On the flip side, you’ll also read about foods to eat to get rid of cold sores or prevent them from coming back. It usually goes something like this:

  • Eat foods with lysine
  • Eat more alkaline foods
  • Eat more fruits and vegetables
  • Take supplements like lysine, zinc, vitamin C, medicinal mushrooms, monolaurin, etc.

Sounds simple enough, right?

The problem is, if you were to follow all those rules about what to eat and what not to eat with cold sores, you’d be eating a very restrictive diet.

You’d never eat foods you enjoy, like chocolate…

You’d never be able to have a drink with friends because there’s arginine in beer…

And forget eating anything with grains in it like bread, pasta, etc.

Basically, you’d live in fear of eating pretty much anything but boiled chicken and beets since everything else has been blamed for triggering a cold sore at one time or another.

Where most advice about what foods to eat and to avoid with cold sores fails

Except here’s the problem with most advice regarding foods to avoid with cold sores: almost none of it takes into account the life cycle of the herpes virus and the stages a cold sore goes through.

If it did, there would be a distinction between what foods trigger cold sores to come back and which ones you should avoid during an outbreak. Because what prevents cold sores is different from what gets rid of an existing cold sore.

I’m here to tell you the foods you should avoid with cold sores are not the ones you’ve been told.

Not exactly anyway.

You don’t need to give up your favorite foods, like peanut butter and chocolate, just because they contain arginine.

You can have a drink here and there, so long you don’t go crazy.

You don’t need to be afraid of ANY food triggering a cold sore, because foods in isolation have little to no bearing on the activity of the herpes virus.

You just need to understand how the foods you eat affect the herpes virus and how cold sores get triggered in the first place.

With that in mind, let’s take a look at some of the most common suggestions regarding diet related strategies and foods to avoid with cold sores and how they don’t deal with the real issues behind cold sores.

But first…

The stages of cold sores

To understand why certain diet strategies for cold sores work and others don’t, you need to understand the life cycle of the herpes virus and the different stages a cold sore goes through.

In a nutshell, there are roughly 5 stages to a cold sore:

  1. The latency stage: In between cold sores, the herpes virus is dormant, hiding in the ganglia of your cranial nerves, until it gets reactivated.
  2. The tingling stage: After reactivation, the herpes virus travels down the trigeminal nerve where it infects healthy skin cells in your lips. You feel that tingling sensation and notice a slightly red, inflamed spot on your lip. A bad sign of things to come.
  3. The blister stage: The herpes virus has infected many healthy skin cells. The red inflamed spot gives way to blisters that gradually fill up with fluid. The itchiness gets dialed up to eleven.
  4. The ulcer stage: The blisters burst and give way to open sores. This is the most painful, gross and unpleasant part of the cold sore. Oh, and contagion is at its worst.
  5. The scabbing stage: Your immune system finally defeats the virus and the open sores slowly crusts over to form a scab. The cold sore is basically over and your body is now in damage control.
  6. The healing stage: As the skin under the scab slowly heals, your scab degrades and falls off. A fresh patch of pink skin grows where the cold sore used to be. At this point, what’s left of the herpes virus returns to the latency stage by climbing back up the trigeminal nerve to hide in the ganglia.

That’s a basic rundown of the different cold sore stages.

But when it comes to foods to avoid with cold sores, you can think of the herpes virus as having 2 states:

  • The active state: When you have any cold sore symptom whatsoever (tingling, blisters, ulcers, etc.).
  • The inactive or latency state: When you don’t have any symptoms.

This makes things simple; you either have a cold sore or you don’t. But more importantly, it emphasizes the importance of the latency state as being at least as important as the active state.

In fact, I personally believe that people with cold sores should be far more interested with the latency state than the active state.

Why? Simply because if you can find treatments, prevention methods and foods that KEEP the herpes virus in a state of latency, you simply will not have a cold sore.

However, when looking for information on foods to eat or foods to avoid with cold sores online, every recommendation you’ll find is tailored to the active state of the herpes virus. Meaning they focus more on fighting cold sores when they happen rather than keep them from coming back.

Case in point, most information about foods to avoid with cold sores revolves around 2 things: lysine and arginine.

Lysine and arginine

Where ever you go, you’re told to avoid peanut butter, nuts and seeds, chocolate, wheat based products, etc. because they are all foods that contain arginine which triggers cold sores.

And then there’s lysine. The yin to arginine’s yang.

Foods that contain lysine or taking lysine supplements is said to prevent cold sores from happening.

But what do these two amino acids really do for cold sores?

Will eating less arginine and more lysine actually help you stop or prevent a cold sore?

Where the lysine and arginine craze all started

The whole idea that arginine is bad for cold sores and that you should avoid foods that contain it started in the late sixties when a group of researchers found that a high concentration of arginine increased replication of viral particles in infected cells.

Then, in the late seventies, a study from a team led by a doctor named Christopher Kagan found that when they gave people with cold sores a daily dose of lysine, their cold sore symptoms were diminished.

Finally, in the early eighties a study on cultured cells found that when cells infected with the herpes virus were exposed to a higher concentration of lysine than arginine, viral replication was inhibited.

Of course, these aren’t the only three studies to look at the effects of arginine or lysine on viral replication. But when it comes to cold sores, they are the three most talked about.

Together, these three studies suggested that high levels of arginine increased the replication of the herpes virus, while high levels of lysine suppressed the replication of the herpes virus.

And to cold sore sufferer’s, that translated to “avoid foods that contain arginine and eat more foods that contain lysine”.

Hallelujah! A “cure” had been found!

Or had it…

It turns out that avoiding foods that contain arginine and taking lysine supplements isn’t the great cold sore treatment it’s been made out to be.

Since those studies have been published, multiple studies have come out in more recent times that directly contradict the claims that high lysine/low arginine foods fight cold sores.

Let’s take a look

Avoiding foods with arginine for cold sores may not be what it’s made out to be

First of all, in 2009 a study came out reporting that arginine can actually help inhibit the replication of the herpes virus if it’s introduced early enough in the replication process. At worst, it was found that it does not help viral replication at all.

Secondly, a study published in 2012 found that arginine inactivates particles of the type 2 herpes virus (the virus mostly responsible for genital herpes) and increases the survival rate of mice infected with the virus. Of course, even though type 2 HSV and type 1 HSV are closely related and both can cause cold sores, they aren’t exactly the same. That being said, the two viruses aren’t different enough for arginine or any other antiviral to have opposite effects on them. If arginine inactivates HSV-2, there’s a good chance the amino acid has a similar effect on HSV-1.

Add that to the fact that arginine plays many important roles in the immune system and it seems that avoiding foods with arginine to stop or prevent cold sores isn’t all it’s made out to be. The most recent evidence we have suggests that arginine doesn’t do much to enhance cold sores or the activity of the herpes virus.

It seems though that these studies have been mostly ignored by the cold sore medical community.

Why? I have no idea.

But it hasn’t stopped people from telling cold sore sufferer’s to stop eating any and all foods that contain arginine. Stuff like peanut butter, chocolate and most kinds of nuts.

Hell, people will even tell you to avoid super healthy foods just because they contain slightly more arginine than they do lysine.

Like spinach for example. Sure it contains a bit more arginine than lysine. But it’s a veggie. And the total amount of arginine it contains is insignificant in the larger context of a healthy diet that contains a good amount of protein.

Plus, spinach contains an ungodly amount of healthy vitamins and minerals that are crucial to the proper function of your immune system. You know, that way it can actually fight off viral infections…

So if you’re avoiding foods with arginine for the sake of cold sores, you just may be shooting yourself in the foot and missing out on all the important things arginine does in your body.

Not to mention that avoiding foods that contain arginine is a massive pain in the butt. Are you really going to look at the protein and amino acid content of ALL the foods you eat?

No? Then how can you be sure you’re not taking in “too much” arginine?

You can’t. Heck, nobody even seems to know how much arginine is too much arginine.

You have no target, nothing to aim for. Just generic advice to “avoid arginine” or to “eat more lysine than arginine”. Not very practical, is it.

But you know what the real kicker is when it comes to avoiding foods that contain arginine? It’s that…

you can’t avoid arginine even if you try.

See, your body has the ability to make arginine.

That’s right.

Whatever arginine you don’t get in your diet, you’re body will make up the difference by transforming other amino acids into arginine.

So in reality, to “rid” your body of arginine, you’d have to avoid foods that contain arginine, yes, but also foods that contain citrulline and glutamine.

You up for that?

Plus, citrulline and glutamine probably play a role in god knows how many biological functions, so avoiding them probably isn’t a great idea in the first place.

Look, trying to avoid specific amino acids for the sake of fighting cold sores is dumb. Your body needs them whether they are essential, semiessential, or non-essential. The only difference between those 3 types is how your body acquires them (either through diet or by making them itself).

So when it comes to foods to avoid with cold sores, don’t waste your time trying to cut out arginine. Not only does it not help cold sores, you can’t avoid it even if you try.

The effect of lysine on cold sores

What about lysine?

If eating arginine does not trigger cold sores and you can’t avoid it, maybe it’s the lysine that PREVENTS them.

Once again, the science here is murky.

While studies like the one published by Dr. Kagan in the late seventies claimed that taking lysine helped fight the symptoms of cold sores, there have been many studies since that have found the opposite to be true.

For example, a study performed in the eighties failed to replicate the findings of doctor Kagan’s team. In fact, the researchers found no significant improvement for either treating cold sores or preventing future outbreaks. The severity, duration, and recurrence rate was not reduced in patients taking lysine.

And that’s not the only study unable to replicate the findings of doctor Kagan. Another one found no effect of lysine on the re-occurrence rate or healing speed of cold sores whatsoever.

Then, there’s this study that found that lysine is flat out not effective in the treatment or prevention of herpes virus infections… in cats. Ok, so take this one for what it’s worth, keeping in mind that human and cat biology are pretty different…

But let’s consider one final study from 2017. It reviewed of all the studies done on the effect of lysine on cold sores since the seventies. ALL of them. And what did they find after compiling all the evidence? They found that lysine supplementation appears to be ineffective for the prophylaxis or treatment of herpes simplex lesions.

So people way smarter than me are coming to the same conclusion about lysine and cold sores.

What I take of it is lysine most likely isn’t the cold sore cure everybody makes it out to be.

The lysine to arginine ratio

Of course, some people say that it’s not high lysine or low arginine alone that prevents cold sores. Rather, it’s the lysine to arginine ratio because both amino acids compete together and that by consuming more lysine, you’re blocking the virus enhancing effects of arginine.

But if that were true, you would never have to avoid arginine and the foods that contain it at all.

Why? Because if you go down the list of animal proteins like chicken, pork, beef, fish, etc, that a lot of people eat daily, they almost all contain higher levels of lysine than they do arginine. And if that’s true, shouldn’t the lower amount of arginine be “blocked” by all that lysine?

If that were the case, everybody would be deficient in dietary arginine. If lysine blocks arginine, it’s not specific to herpes infections, that’s for sure. And besides, I’m pretty sure there would be a whole other subset of health issues associated with arginine deficiency.

Now I don’t know this for sure, but odds are lysine and arginine don’t significantly interfere with each other. Sure, they may use the same transporter here or there (I’ll be honest, I haven’t checked). But to think that taking lysine is going to completely negate the effects of arginine? Nonsense.

The fact is, if you eat real meat on a regular basis, there’s really no need to worry about getting enough lysine. You do.

However, if you don’t eat meat and have a diet low in protein, well you may run into problems related to lysine deficiency. After all, lysine is an essential amino acid and plays many important roles in the human body. In that context, it’s likely that lysine supplementation does have a positive effect.

The one moment when lysine and arginine may be important for cold sores

That being said, there may be a moment during the cold sore cycle when eating foods with lysine and avoiding foods with arginine could be important.

Let me explain.

Assume for a moment that everything I just said is BS and that arginine and lysine are important for cold sores.

According to the supporting scientific studies, arginine feeds the replication cycle of the herpes virus and lysine inhibits it.

If that’s true, it means that for either of these amino acids to have any effect whatsoever, the herpes virus must be in a state where it is actively replicating. And the only moment when that happens is DURING a cold sore outbreak, i.e. when healthy cells have been infected and hijacked by the virus. From the moment the tingling begins until the moment the cold sore dies off and a scab has formed.

On the flip side, this means that foods that contain lysine or arginine cannot have an effect while the virus is in a state of latency. Because if the virus it’s not actively replicating, there is no process for lysine to interfere with or arginine to enhance.

Given this hypothetical situation, i.e. if avoiding foods with arginine and/or eating foods that contain lysine is important, it’s DURING a cold sore.

Not before, not after. During.

With that in mind, you could presumably shorten your cold sore by drastically increasing your intake of lysine and dropping your intake of arginine from the moment you feel that tingling sensation until your cold sore turns into a scab or goes away altogether.

Again, let me reiterate that I’m not personally convinced either lysine or arginine have much of an effect on cold sores. I’m just saying that if you were to take lysine, high doses DURING a cold sore is the way to go.

But don’t hold your breath thinking you can take lysine supplements and avoid arginine containing foods in between outbreaks in the hopes of preventing cold sores from coming back.

The acid alkaline balance for cold sores

Another idea that gets floated around a lot when it comes to foods to avoid with cold sores is that you should be eating foods that alkalize your body and avoid foods that acidify it.

In short, foods that alkalize such as vegetables, fruits and nuts are good for you whereas foods that acidify like any type of meat, dairy or alcohol are bad for you. Eat more alkaline foods than acidic ones, and you’re good to go.

The reasoning behind this approach is that cold sores get triggered when your body is in a more acidic state and that the herpes virus will leave you alone when you’re in an alkaline state.

I’m here to tell you the idea your body can even be “acidic” is hogwash.

First of all, the foods you eat can’t really affect your body’s acidity level.

See, your body’s pH must remain in a very, VERY narrow range or else you end up with serious medical problems (read: coma or death). In fact, science says that your body’s pH must remain between 7.35 and 7.45 and if you get outside of that range, you’ll start feeling horrible. Get too fat from that and you’re looking at a coma.

To make sure this doesn’t happen, your body has multiple mechanisms in place to make sure your pH stays exactly where it needs to be.

And what is the primary mechanism for maintaining the acid/alkaline balance?


Yes, breathing.

See, the carbon dioxide you expel when you breathe out is directly related to maintaining the delicate pH balance of your body.

You want to alkalize your body? Go outside and get some fresh air.

Breathe deep, and breathe hard for a minute or two, until your fingers and toes are tingling.

You want to acidify your body? Hold your breath until you pass out.

Just think about that last sentence. Your body would rather knock you out and retake control rather than let you increase your pH levels by not breathing or breathing too much. That should tell you something about the importance of keeping a balanced pH and how tightly your body controls it.

Look, I’m not going to say that the recommendations of the acid/alkaline diet are nonsense, like eating more vegetables and fruits or eating less junky, processed foods. Those are good ideas.

I’m just saying that choosing what foods you eat in the hopes of altering your body’s pH is a waste of time because you don’t actually have any control over it.

And as for the link between your body’s pH and cold sores? Well, how can the pH of your body trigger a cold sore if the foods you eat don’t affect it? The truth is, cold sores get triggered by a completely different subset of biochemical factors.

Foods to eat and foods to avoid with cold sores

Based on what we’ve talked about so far, the relationship between food and cold sores can be broken down into two categories:

  • Foods to eat and avoid during a cold sore outbreak
  • Foods to eat and avoid to prevent a cold sore outbreak

Now, common wisdom says that it all boils down to the same thing whether you’re fighting off a cold sore or trying to prevent your next one: avoid foods that contain arginine and eat foods that contain lysine.

But as we’ve seen in previous sections, avoiding arginine isn’t your best bet and taking lysine is a crapshoot.

So if not arginine or lysine, which foods (if any) are good/bad for fighting cold sores and which ones are good/bad for preventing them?

Examples of foods to eat and foods to avoid to PREVENT cold sores

In my experience, the only foods you should make a point to avoid if you don’t want to get cold sores are foods that your body isn’t naturally equipped to process very well, mainly:

  • Highly processed foods
  • Refined sugars
  • Alcohol

So really, any kind of junk food where you’re not immediately sure what went into its preparation (Cheetos, Cheez-whiz and Lucky Charms come to mind).

Candy, desserts, juices and soft drinks are packed full of sugar which can trigger a cold sore.

And what bad things can I say about alcohol that haven’t already been said. There are few things worse for your health than alcohol. And on a personal note, nothing triggers a cold sore for me like getting drunk.

But beyond just avoiding specific foods, I believe it is their over-consumption that’s the problem.

I’m not going to sit here and tell you that eating one bowl of Lucky Charms is going to do much damage to your health.

Nor am I going to demonize having a couple of beers each week.

You have to think about the sum total of “crap” you’re putting in your body.

If your diet consists mostly of processed junk foods, it shouldn’t be a surprise if your cold sores keep coming back.

But if you eat a healthy diet high in clean protein and vegetables, having junk food or alcohol IN MODERATION probably isn’t going to do much damage.

It’s not about avoiding guilty pleasures completely (hey, I like Cheetos as much as anybody, maybe even more). It’s about keeping them as nothing more than guilty pleasures.

And of course, if you’re still inclined to try lysine after reading this page, during your outbreak is the time to go crazy with it. Eat more chicken and fish that normal, take lysine supplements multiple times daily. Go nuts. Like we discovered, if lysine works at all, it’s during your outbreak.

Examples of foods to eat and foods to avoid during a cold sore outbreak

In my experience, there aren’t really any foods you can eat and/or avoid that will reduce the duration of a cold sore. Because by the time your cold sore is out and proud, the infection has already taken hold.

And by the time you’ve eaten enough of any “antiviral” containing food for it to have an effect, your immune system and cold sore treatment will have done most of the work anyway.

The only things that you can swallow that MAY help you get rid of it faster are things that contain high concentrations of antiviral compounds. Certain supplements and prescription pharmaceuticals come to mind.

Also, like we mentioned previously, if you’re inclined to think avoiding arginine actually works, during your outbreak is the time to go for it. Again, I’m not convinced this will do anything. But if you do avoid arginine, cut out nuts, legumes and wheat based products.

Of course, there is also the physical aspect of cold sores that must be taken into account. Foods that require you to open your mouth wide are tricky to eat with a cold sore, especially once it crusts over and turns into a scab. Same goes with soup. Stick to food you can eat in small bites and that don’t require you to open your mouth wider than a python swallowing a baby elephant.

But beyond those very basic tips, there’s not much you can do to stop an in progress cold sore in terms of the foods you put or don’t put in your mouth beyond eating a healthy diet high in vegetables and protein.


When it comes to foods to avoid with cold sores, I believe most advice being given today seriously oversimplifies how a latent infection actually works.

As we’ve explored, it’s not just as simple as “eat lysine and avoid arginine”.

See, the real reason cold sores keep coming back again and again really has nothing to do with lysine or arginine. Instead, they come back only when a very specific biochemical pathway gets triggered.

So if I had to boil down what foods to avoid with cold sores, I’d say this:

  1. Avoid alcohol
  2. Avoid sugar
  3. Avoid junk foods

Of course, when I say avoid, I mean go easy on them. Only have them once a week (if you want) and try to consume only one at a time at any given moment. In my experience, nothing triggers a big nasty cold sore faster than consuming all three together.

It’s not sexy advice, I know.

But trying to zone in on this food or that food because it contains this compound or that antiviral molecule is a waste of time. Focus on eating healthy and consuming the foods mentioned above in moderation and you’ll likely see a drastic reduction in your cold sores.

And if you don’t? Then your issue isn’t with what foods to avoid with cold sores. It’s probably because other factors in your life are causing the herpes virus to constantly reactivate.

If you want to learn more about cold sore prevention, make sure to read the free first chapter of Cold Sore Control by signing up to our email newsletter.

It reveals the specific biochemical reason why cold cores keep coming back and, more importantly, how to make sure they don’t ever bother you again.

More on foods to avoid with cold sores: