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What Can You Do for Cold Sores?

Treating cold sores at the first hint of a tingle often results in quick healing. One reader combines medications with home remedies.

Cold sores are painful and unsightly lesions that result from herpes simplex virus 1 (HSV-1). People also call them fever blisters, as they tend to pop up when a person is suffering from an infection that causes a fever. Cold sores form blisters and crust over as they are healing. They occur on the skin around the mouth as well as on the lips. There is no cure, but there are medications and myriad home remedies. This reader could not tolerate a common home remedy: L-lysine.

Acyclovir Worked for Cold Sores!

Q. I am prone to cold sores/fever blisters and find that acyclovir works very well. Before that I took L-lysine for several years hoping to prevent outbreaks. However, I discovered that L-lysine caused me nightly leg cramps.

My internist, who wasn’t familiar with acyclovir until I told her about it, will not give me a refill without my calling for it. Consequently, I am very careful to call for a refill as I am finishing a prescription because I need to take the pills at that very first tingle. People who haven’t had fever blisters might not understand that urgency.

A. There are several antiviral medications that work quite well against herpes simplex, the virus that causes cold sores. Acyclovir (Zovirax) was the first to be developed, but doctors can also prescribe famciclovir (Famvir) or valacyclovir (Valtrex). We’re a bit surprised that your internist was unaware of such medications.

Taking any of these herpes drugs at the earliest hint of an outbreak works best. That is also true of other antiviral drugs such as oseltamivir (Tamiflu) or baloxavir (Xofluza) against influenza. The faster someone is diagnosed and treated for viral infections (including COVID-19) the better the outcome.

Combination Approach to Combat Cold Sores:

Q. I’d like to share my approach to cold sores. Aside from preventive tactics such as avoiding stress and fatigue, as well as exercising, eating appropriately (getting all your vitamins and proteins, increasing lysine intake and avoiding arginine-rich foods), there is a winning formula of four treatments that fight any outbreak.

As soon as I feel the dreaded tingle, I:

  1. take L-lysine supplement pills daily,
  2. take two prescription valacyclovir pills every 12 hours for two days,
  3. put prescription Zovirax cream on the sore every three hours, and
  4. apply Abreva cream at the same time as Zovirax (mix both together and apply generously).

This combination has been working for me for eight years.

A. Thank you for sharing your unorthodox combination. Such an approach has not been tested in clinical trials, but it does make some sense.

Valacyclovir (Valtrex) is an oral antiviral medicine proven to shorten the duration of cold sores. Topical acyclovir (Zovirax) works in a similar manner to keep the virus from replicating. Abreva is an OTC anti-herpes cream that works differently from acyclovir, so perhaps the combination would be more effective than either drug alone. We could find no research to support your strategy, though.

Valacyclovir Pills vs Zovirax Cream:

Another reader wanted to share this experience:

Q. I have had cold sores for years, generally when I’ve been stressed. While working, I had good insurance and I always used prescription Zovirax cream. Now that I’m retired, this cream is not covered by my Medicare. The cost for a small tube requires a home mortgage.

My dermatologist recommended two prescription valacyclovir pills every 12 hours for one day. Comparing the pills to the cream, he said it’s like taking a gun to a knife fight – an obvious reference to Indiana Jones. He is right on. At the first sign of a tingle, I take two pills, and the cold sore is gone the next day. The cream used to take several days to get rid of it and the pills cost a lot less than the cream.

A. Thank you for the testimonial. Until you alerted us, we had no idea that Zovirax cream was so pricey! In our area we found it would cost over $900 for a 5-gram tube. Even the generic acyclovir cream is unbelievably expensive at more than $800.

Cold sores are caused by herpes simplex virus type 1 (HSV1). There’s no cure for this virus that shows up as a lesion when the immune system isn’t able to hold it back. But oral medications like acyclovir and valacyclovir can quickly heal the lesion. It makes sense to use the tablets as you do. The cost is modest, a few dollars for a day’s supply.

Home Remedies to Conquer Cold Sores:

People who have recurrent cold sores may be miserable.

One woman wrote:

“I have suffered from cold sores my whole life (59 years). I get them when I’m sick, when I’m about to be sick, when I’m out in the cold, wind or sun and when a big important event is on the horizon. They crack and bleed and have been a nightmare for me my whole life.”

So, what’s a cold sore sufferer to do? Antiviral medications such as acyclovir (Zovirax), famciclovir (Famvir), penciclovir (Denavir) and valacyclovir (Valtrex) can be used to speed healing of cold sores by a few days. These prescription medicines can also be taken daily to prevent outbreaks in people who get them frequently.

Others have found home remedies that work for them.

Here is one reader’s story about acidophilus:

“Over 25 years ago, while in college, I continually developed cold sores on my lips due to stress. This was devastating for my dating life.

“Then I read about a natural remedy. Taking acidophilus pills at the first tingle of a soon-to-be-visible cold sore bubble on my lip prevented an ugly two-week-long outbreak. I take tablets several times a day, and also make a paste of the tablets and apply it to the cold sore. Used early enough, this keeps the bubble from bursting and forming a scab.

“Since graduation from college, I have had no cold sores until recently. Instead of using my old remedy, I spent $15.00 at the drugstore on a tube of ointment. It promised quick relief, but it still took seven days for the sores to heal.

“Yesterday, I felt the familiar tingling and found several cold sore bubbles forming. I immediately went to the vitamin store and bought acidophilus. I followed my previous regimen and I am glad to report the itching is gone and the bubbles have largely disappeared.”

Many readers have used a different dietary supplement to ward off cold sores.

L-lysine is a perennial favorite:

“I have an answer for cold sores. I used to get several a month, to the point where I have a scar on my bottom lip. I finally asked the pharmacist what I could do and was told to use L-lysine. I have not had a cold sore in five years!”

Another reader added this advice: “I have been taking L-lysine for HSV-1 for over 20 years, and it has kept me virtually outbreak free. It is also important to avoid nut products and chocolate. Together those two things have worked better for me than Zovirax, which I took for a year as part of a study at the University of Rochester.”

Other approaches include buttermilk and lemon balm (Melissa officinalis). Whether a person chooses a prescription antiviral drug or a home remedy, the sooner the treatment is used the better it will work.

Hanna notes:

“I have found that peroxide on a Q-tip at the first sign of a lesion on my lip will dry it up. Let it bubble and it seems to kill it, but has to be done first sign.”

CC prefers tea tree oil:

“Whenever I feel the itching coming on from a probable cold sore on the horizon, I use Tea Tree Oil several times a day. It does not smell real good, but it stops the cold sore dead in its tracks. You can buy it at the drug store in the vitamin section. Works wonderfully!”

Mary O. finds relief in the fruit drawer:

“I heard about Kiwi fruit for cold sores on you newspaper column. This has been a total magic bullet for me. I am surprised it doesn’t show up on your online list.

“At first tingling, eat two kiwis; then one a day until it disappears. If you eat a Kiwi fruit once a week, you will not get cold sores. But if it starts, eat a few more. This is the most valuable thing I have learned from your wonderful columns. Kiwi fruit has something that zaps colds sores. Don’t buy the $18+ creams. Buy a few Kiwis. It is a truly amazing remedy.”

Dave takes vitamin C:

“I’ve also had cold sores for decades. A couple thousand mg of vitamin C has been great for prevention, and when one gets past that, I put zinc oxide ointment (white) on it and it “dries” it away within a day or two!”

Rollie uses vitamin C topically:

“I have used Vitamin C tablets that are not coated. I wet them and press them against the sore. It burns a little, but I have never had a blister develop when I have applied a tablet.”

AS sticks with tried-and-true L-lysine:

“I’ll stick to the L-lysine: 1st time 1gm, then 1 gm 2x a day until it’s gone.”

What Works For You?

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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