How to Stop a Cold Sore from Growing

Co-authored by Andrea Rudominer, MD, MPH

Last Updated: February 18, 2023 References

Cold sores are caused by a herpes simplex virus, and are very contagious, passed on through touch. About 90% of adults test positive for the infection, even if they have never had symptoms.^{[1]
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Research source} The sores are small blisters that often appear on and around your lips. They typically heal within two to four weeks.^{[2]
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Trustworthy Source
Cleveland Clinic
Educational website from one of the world's leading hospitals
Go to source} There is no cure or vaccine for the infection, but swift action and diligent hygiene can help you limit the growth and spread of cold sores.

Method 1

Method 1 of 3:

Treating a Cold Sore

1
Know the signs. If you have experienced a cold sore before, you may be able to get a sense for when an outbreak is going to occur. You may experience itching, burning, or tingling around your lips about a day before the cold sore appears.^{[3]
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Trustworthy Source
Johns Hopkins Medicine
Official resource database of the world-leading Johns Hopkins Hospital
Go to source} If you believe you are about to get a cold sore, you can begin treatment right away and potentially shorten the duration of the outbreak. You can also make sure you don't accidentally spread the virus to anyone by refraining from contact.
- Outbreaks commonly occur when you experience a great deal of stress, are overly tired and fatigued, or when you have a viral infection or fever (cold sores are also known as "fever blisters").^{[4]
  X
  Trustworthy Source
  Johns Hopkins Medicine
  Official resource database of the world-leading Johns Hopkins Hospital
  Go to source}
2
Use an over the counter topical treatment. There are a number of antiviral creams that you can get over the counter without a prescription to tackle cold sores. These are designed to speed up the healing time for the sore, they will not actually get rid of the herpes simplex virus nor will they prevent you suffering from future outbreaks. They will generally only be effective if you apply them soon after the sores appear.^{[5]
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Trustworthy Source
Johns Hopkins Medicine
Official resource database of the world-leading Johns Hopkins Hospital
Go to source}
- The antiviral creams to look out for include acyclovir, penciclovir, and docosanol.
- In a study penciclovir was reported to have the highest antiviral effectiveness.
- You will need to apply these creams for four or five days, and up to five times each day.
- When you apply the cream be sure to use a cotton swab or wear a disposable rubber glove so you don't contaminate your hands.
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3
Consider an oral antiviral. For many of these creams, there are alternatives in pill form. You can take these orally if you prefer that to a topical cream. Oral medications may be more effective than topical creams. They will certainly not require to touch the sores in any way, which can help limit their spread. If you are uncertain, ask your doctor or pharmacist for advice.^{[6]
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Trustworthy Source
Cleveland Clinic
Educational website from one of the world's leading hospitals
Go to source}
4
Soothe the pain. As well as the antiviral treatments, you can consider taking some painkilling medicine to ease the pain and lessen the irritation the sores are causing you. If you find yourself battling to avoid itching or scratching the cold sores, try using a non-antiviral cream to lessen the irritation. These will not treat the cold sores or make them heal faster on their own. Ask for pharmacist for a recommendation.^{[7]
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Trustworthy Source
National Health Service (UK)
Public healthcare system of the UK
Go to source}
- Regular painkillers such as ibuprofen and paracetamol can be taken to ease the pain of sores.
5
Use something cold to ease irritation. Applying something cold to the area where you have a sore can also help to relieve the pain and irritation. Lightly hold an ice cube against a sore, or place a cool damp cloth on your face.^{[8]
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Research source} A cool compress can reduce redness and encourage the sore to heal.^{[9]
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Trustworthy Source
Cleveland Clinic
Educational website from one of the world's leading hospitals
Go to source} Try placing a cool towel on the sores three times day, each time for twenty minutes.
6
Consider natural remedies. Although natural remedies are unreliable compared to medications, there are a number of things which have been reported as helping tackle cold sores. One of these is L lysine, an amino acid that you can buy as a supplement and as a cream. Modest application to the cold sore may help. Alternatively, propolis, sometimes called synthetic beeswax, is thought to shorten the duration of a cold sore outbreak if applied to the relevant area early and frequently.
- A cream of rhubarb and sage has been cited as a homemade alternative to acyclovir cream.^{[10]
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  Trustworthy Source
  PubMed Central
  Journal archive from the U.S. National Institutes of Health
  Go to source}
- Stress has been linked to cold sore outbreaks, so lowering your levels of stress could help.^{[11]
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  Trustworthy Source
  MedlinePlus
  Collection of medical information sourced from the US National Library of Medicine
  Go to source}
- A topical ointment of 1% lemon balm or 0.5% aloe can help your cold sore heal if you’re looking for a natural remedy.^{[12]
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  Expert Source
  
  Andrea Rudominer, MD, MPH
  Board Certified Pediatrician & Integrative Medicine Doctor
  Expert Interview. 13 April 2020.}

Method 2

Method 2 of 3:

Maintaining Good Hygiene

1
Keep your hands clean. If you want to stop a cold sore from growing or spreading it's essential to ensure that you maintain good hygiene. Keeping your hands clean by regularly washing them with soap and water will limit the chances of it spreading. You should try not to touch the cold sore at all, but you might do it involuntarily, so keeping your hands clean is essential.^{[13]
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Research source}
- If you do touch the cold sore, be sure that you wash your hands immediately afterwards. If you don't, you could spread the virus to other parts of your body.
2
Don't risk transporting the virus to someone else. You should be conscious that an important part of maintaining good hygiene is about avoiding the risk of spreading the virus to another person. You can take steps against this by doing simple things, such as not sharing objects which come into contact with the area around your cold sore. Don't share items such as towels, cups, lipgloss, a razor, or toothbrushes.^{[14]
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Trustworthy Source
American Academy of Dermatology
Professional organization made of over 20,000 certified dermatologists
Go to source}
- It is also important not kiss anybody or perform oral sex. This can transport the virus to your partner.
- If someone has oral sex while they have a cold sore, they can transmit the virus to their partner and cause herpes in the genital area.^{[15]
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3
Wash your face gently. If you have a cold sore it can be awkward to wash your face. The key thing to remember is that you don't want to irritate the cold sore. Wash your face twice a day and only use mild soap. If this is irritating your sores, consider using just water. Remember to thoroughly wash your hands before you wash your face.

Method 3

Method 3 of 3:

Ensuring You Don't Irritate Your Cold Sore

1
Don't touch it. If you have a cold sore and want to stop it growing and spreading, it's very important that you resist the urge to touch it, pick it, scratch it, or rub it. Touching a sore is surefire way to exacerbate it and risk spreading to other parts of your body.^{[16]
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Research source} If you touch the sore there is a risk of the virus spreading to your fingers, a condition known as herpes whitlow.
- It is also possible for your eyes to become infected, potentially leading to scarring, injury and problems with your vision.
- A cold sore can spread to other areas of your skin. If you have eczema this is a particular risk, and can become a serious medical problem.^{[17]
  X
  Trustworthy Source
  American Academy of Dermatology
  Professional organization made of over 20,000 certified dermatologists
  Go to source}
2
Cover and protect the cold sore. To try and stop a cold sore from growing, it can be beneficial to cover it in some way that protects it from irritants but doesn't encourage further infection. Cold sore patches containing hydrocolloid gel can be used to cover and protect the sore. They are an effective way to treat skin wounds, allowing them to heal while under the protection of the patch.^{[18]
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- Alternatively, you can gently apply petroleum jelly over the sore to offer it some protection. If you do this be sure that you wash your hands thoroughly first.^{[19]
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  Research source}
3
Avoid irritants. As well as not touching it, you need to try and make sure no other irritants come into contact with the area where you have the sores. For some people sunlight can trigger outbreaks of cold sores. If this is your experience be sure to use plenty of sunblock to protect your skin, especially around your lips and mouth, or wherever the cold sores usually appear.^{[20]
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- If you have cold sores around your lips and mouth, spicy, salty and acidic food can irritate them. They to avoid these kinds of food when you have a cold sore.^{[21]
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Expert Q&A

Question

How can I stop a cold sore fast using natural remedies?

Andrea Rudominer, MD, MPH
Board Certified Pediatrician & Integrative Medicine Doctor
Dr. Andrea Rudominer is a board certified Pediatrician and Integrative Medicine Doctor based in the San Francisco Bay Area. Dr. Rudominer has over 15 years of medical care experience and specializes in preventive health care, obesity, adolescent care, ADHD, and culturally competent care. Dr. Rudominer received her MD from the University of California, Davis, and completed a residency at the Lucile Packard Children's Hospital at Stanford University. Dr. Rudominer also has an MPH in Maternal Child Health from the University of California, Berkeley. She is a Member of the American Board of Pediatrics, a Fellow of the American Academy of Pediatrics, a Member and Delegate of the California Medical Association, and a Member of the Santa Clara County Medical Association.

Andrea Rudominer, MD, MPH

Board Certified Pediatrician & Integrative Medicine Doctor

Expert Answer

A 1% topical ointment of lemon balm oil at the start of the cold sore can help heal it faster. A 0.5% aloe vera extract can also be helpful. If you're a fan of essential oils, mix 5 drops of eucalyptus, 3 drops of bergamot, and 2 drops of tea tree oil in 1 ounce of a carrier oil. Apply that topically to help the cold sore heal.
Question

What cough drops can I take that will not irritate my cold sore?

Chris M. Matsko, MD
Family Medicine Physician
Dr. Chris M. Matsko is a retired physician based in Pittsburgh, Pennsylvania. With over 25 years of medical research experience, Dr. Matsko was awarded the Pittsburgh Cornell University Leadership Award for Excellence. He holds a BS in Nutritional Science from Cornell University and an MD from the Temple University School of Medicine in 2007. Dr. Matsko earned a Research Writing Certification from the American Medical Writers Association (AMWA) in 2016 and a Medical Writing & Editing Certification from the University of Chicago in 2017.

Chris M. Matsko, MD

Family Medicine Physician

Expert Answer

Most cough drops will not irritate your cold sore if the sore is on the outside of your mouth. Try Halls, Cepacol, or Ludens — these might work best for you.

Warnings

Be alert for signs of a secondary infection, such as a high temperature, greenish-yellow puss, or swelling. Go to a doctor if you experience of any of these.

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You should contact a doctor if the pain is such that you cannot eat or drink, you have sores on your genitals, near your eyes or nose, or any redness, pain or swelling in your eyes.

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If the sores don't heal after two weeks, or new sores keep developing, contact your doctor.^{[22]
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