Fever Blister Causes + 15 Natural Remedies - Dr. Axe

Fact Checked

This Dr. Axe content is medically reviewed or fact checked to ensure factually accurate information.

With strict editorial sourcing guidelines, we only link to academic research institutions, reputable media sites and, when research is available, medically peer-reviewed studies. Note that the numbers in parentheses (1, 2, etc.) are clickable links to these studies.

The information in our articles is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

This article is based on scientific evidence, written by experts and fact checked by our trained editorial staff. Note that the numbers in parentheses (1, 2, etc.) are clickable links to medically peer-reviewed studies.

Our team includes licensed nutritionists and dietitians, certified health education specialists, as well as certified strength and conditioning specialists, personal trainers and corrective exercise specialists. Our team aims to be not only thorough with its research, but also objective and unbiased.

The information in our articles is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

Fever Blister Causes + 15 Natural Remedies


Fever blister - Dr. Axe

A fever blister is pretty common, as it easily spreads from person to person through direct contact. Also called cold sores, fever blisters can be uncomfortable and unattractive. They begin as red and swollen blisters that eventually develop scabs.

Fever blisters are caused by the herpes simplex virus, an infection that may cause only a single fever blister or an outbreak of several fever blisters over the course of many years. Similar to the symptoms of a canker sore and oral thrush, fever blisters cause painful sores that can become worse when you have a weakened immune system.

By boosting the immune system through a healthy diet, making lifestyle changes and taking precautions during periods of active breakouts, you can help keep the herpes virus dormant and limit the outbreak of fever blisters.

What Is a Fever Blister?

A fever blister is caused by herpes simplex virus type 1 (HSV-1). The virus is passed from person to person by entering the body through a break in the skin around or inside the mouth. It spreads when a person touches a fever blister or touches the infected fluid, which can happen by kissing an infected person, touching her saliva, or sharing glasses and utensils. (1)

Fever blisters are groups of small blisters that are usually found on the lip and around the mouth. The blister can be painful and cause the skin around the fever blister to look red and swollen.

There are usually several stages of a fever blister. You first experience a tingling, itching and even burning sensation around the lips. This is the first sign that a fever blister is developing, and you should begin using antiviral herbs, essential oils and creams the moment you notice these symptoms.

Within 24–48 hours, the blister typically forms on the border of the lips and skin. Eventually, it breaks open and begins to ooze, and then it dries out and crusts over. A scab forms and protects the new skin that’s growing underneath. The virus is contagious until it dries out and scabs over.

Fever Blister Causes and Risk Factors

A fever blister develops as a result of the herpes simplex virus. HSV-1 is a rash of the skin and mucous membranes (in particular, the lips). It’s characterized by irritation, reddening of the skin and blisters that can cause a burning pain. It’s harmless, but often annoying, and it usually heals within 10 days.

HSV-1 is contagious for people who are not already infected by the virus and for those with a weakened immune system, which may be due to chemotherapy treatment or an infection like HIV. Herpes labialis can also spread to the genitals through direct contact during oral sex. (2)

Herpes simplex is a primary infection that usually occurs before the age of 20. Antibodies against the virus are found in about 80 percent of all adolescents. After the primary infection, the virus lays dormant in a person’s immune system throughout her lifetime. However, stimuli, such as fever, menstruation, sunlight, stress and upper respiratory infections, can cause the virus to return.

With primary infections, all oral mucosa can be affected, but relapsing infections are limited to the mucosa of the hard palate or, in older children and adults, the lips. (3)


What is a fever blister? - Dr. Axe


Sores In or Near Mouth: Fever Blister vs. Canker Sore vs. Oral Thrush

Fever Blisters (aka Cold Sores)

  • develop on the outside of the mouth, usually along the edge of the lips
  • are contagious until they scab over and heal completely
  • appear as red, swollen blisters until they break, ooze and form a crust
  • generally heal within 10 days
  • caused by herpes simplex virus-1
  • can be triggered by fever, sunlight, stress, menstruation and upper respiratory infection

Canker Sores

  • develop on the soft tissues inside the cheeks or lips, underneath the tongue, or at the base of the gums
  • aren’t contagious
  • are round with a white or yellow center and a red border
  • generally heal within one to two weeks
  • caused by immune-suppressing viruses, autoimmune disorders and auto-inflammatory disorders
  • can be triggered by an accidental cheek bite, food sensitivity, injury from dental work, hormonal changes, bacteria and stress

Oral Thrush (Candidiasis)

  • develops in the mouth or throat
  • is contagious and can spread through saliva
  • is white spots inside the mouth or on the tongue that may cause sore throat and difficulty swallowing
  • typically clears within seven to ten days
  • is caused by an overgrowth of Candida albicans in the lining of the mouth
  • can be caused by weakened immune system, certain medications (like birth control pills and antibiotics), cancer treatments, diabetes and dentures

Conventional Treatment of Fever Blisters

It’s common for people to take ibuprofen, such as Advil or Motrin, or acetaminophen, such as Tylenol, to reduce the pain of a fever blister. There are side effects to all of these drugs and even a risk of overdose. Do not take more than 4,000 milligrams of Tylenol a day in order to avoid an acetaminophen overdose. For ibuprofen, 800 milligrams four times a day is the safe upper limit.

The most commonly prescribed medications for relieving pain and discomfort from a fever blister are acyclovir (Zovirax), famciclovir (Famvir) and valacyclovir (Valtrex). These antiviral drugs don’t cure the virus, and they don’t help once the blister appears. You must apply them when you feel a cold sore coming on in order for them to be effective. (4) There are mixed results from antiviral medication studies, but the data shows that drugs like acyclovir can reduce the duration of symptoms when taken at higher doses. (5)

The most frequent reported side effects of oral antiviral medications are headache and nausea, which depend on the dose and duration of treatment.

Anesthetic and antiviral creams are also used to treat fever blisters, including lidocaine, prilocaine, acyclovir and penciclovir creams. Both cyclovir and penciclovir reduce the duration of cold sore pain and time to recovery, but they must be applied several times throughout the day, especially penciclovir. (6)

It’s important to understand that even with early detection and prescription medications, the herpes virus cannot be totally cured — so transmission is always still possible. Medications for viruses don’t always work long term, and they’re not a cure-all.

The good news is that the first fever blisters you experience from either HSV virus will most likely be the worst, and then you can expect immunity against the virus to usually improve over time. In fact, by the age of 35, the number of relapses usually decreases. You can speed up tolerance to the virus by making lifestyle changes, boosting your immune system, and using antiviral herbs and essential oils.

15 Natural Remedies for Fever Blisters

While technically the virus that causes herpes is not curable, there are many natural remedies that can put herpes into remission. In fact, many people with the virus don’t experience any symptoms at all, especially long term, once they learn to manage triggers and outbreaks. Here are some simple ways to treat a fever blister once it appears and prevent future outbreaks.

To Get Rid of a Fever Blister:  

1. Zinc

Zinc is needed in many chemical reactions that help rebuild skin and protect the body from viruses and infections. Research shows that topical zinc formulas have been found to be effective for the treatment of fever sores and for prolonging the remission of herpes.

A 2001 study published in Alternative Therapies in Health and Medicine found that participants who began treatment with a zinc oxide/glycine cream within 24 hours of onset of signs and symptoms of oral herpes cut the duration of fever sore lesions significantly when compared to the placebo cream. The mean duration of symptoms was five days. Zinc oxide/glycine cream also reduced the overall severity of symptoms, particularly blistering, soreness, itching and tingling. (7)

A zinc deficiency can increase your risk of developing a fever blister, so boost your zinc intake with zinc-rich foods like grass-fed beef, chickpeas, cashews, pumpkin seeds, yogurt, chicken, turkey, eggs, salmon and mushrooms.

2. Vitamin E

Research published in Alternative Medicine Review suggests that vitamin E soothes the skin and may help to relieve pain and discomfort from fever blisters. It’s an antioxidant that repairs damaged skin and reduces inflammation. (8)

Vitamin E can be taken as oral capsules, or you can boost your levels with vitamin E-rich foods, such as almonds, spinach, sweet potatoes, avocados, sunflower seeds and olive oil.

3. L-lysine

L-lysine is an amino acid that helps treat the herpes virus when taken by mouth or applied directly to the skin. It works by preventing the virus from growing. Several studies found that L-lysine appears to be an effective agent for reducing outbreaks, severity and healing time for recurrent herpes simplex virus infection. (9, 10)

Take 1,000 milligrams three times daily and eat foods that contain L-lysine, such as legumes, fish, turkey, chicken and vegetables.

4. Baking Soda

Baking soda can be applied to a fever blister in order to dry it out, neutralize acids and soothe irritation. You can make a paste with baking soda using either water or fresh lemon juice. Then apply the paste to the fever blister and let it sit for 10 minutes before rinsing.

5. Peppermint Essential Oil

Peppermint oil has antiviral properties and can be used on the skin to heal fever blisters. A 2013 study tested peppermint oil’s defense against HSV-1 and HSV-2. Researchers found that peppermint oil was effective against the virus, especially in the early stages of symptoms. (12) To use peppermint oil, apply 1–2 drops directly on the blister twice daily.

6. Melissa Essential Oil

Melissa essential oil, also known as lemon balm, is used in traditional medicine to treat herpes simplex and promote skin health. It’s the #1 virus-fighting essential oil for fever blisters. This gentle oil is often the herb of choice for treating fever blisters because it’s effective at fighting viruses in the herpes virus family. It can limit the spread of viral infections, which can be especially helpful for people who have developed a resistance to commonly used antiviral substances.

Researchers suggest that Melissa oil is a suitable topical treatment for getting rid of herpes because it has antiviral effects and penetrates the skin. (13)

Simply add 2–3 drops of Melissa oil to a clean cotton ball and apply it directly to the fever blister three times daily.

7. Aloe Vera Gel

You can use aloe vera gel on a fever blister to ease the discomfort and speed the healing process. Research shows that aloe vera gel has medicinal skin care properties. It contains antioxidant vitamins, enzymes, minerals, fatty acids and hormones that help with healing and preventing further infection. (14)

8. Cool Compress

To reduce the redness and swelling of a fever blister, place a cool, wet towel on the blister three times a day for about 20 minutes. Applying ice directly to the blister also helps to reduce inflammation and slow down blood flow to the sore, which helps to relieve pain and swelling.


Seven fever blister prevention tips - Dr. Axe


To Prevent an Outbreak: 

9. Avoid Direct Sun Exposure and Use Sunscreen

Direct sunlight or sunburns may trigger the return of herpes simplex and cause a fever blister. Using sunscreen or avoiding heavy sun exposure may reduce the number of fever blister recurrences that you experience. The use of sunscreen was studied in a crossover trial in which 38 patients were exposed to experimental ultraviolet light. None of the sunscreen-wearing participants developed fever blisters due to herpes labialis, compared with 71 percent of those using a placebo. (15)

Apply the sunscreen to your lips throughout the day, which is done easily with a SPF lip balm. When you are selecting a product for yourself or your child, opt for 100 percent natural and organic sunscreen, as the majority of sunscreens are toxic and cause more harm than good.

10. Avoid Direct Contact with Fever Blisters

Because the virus can spread from person to person, avoid direct contact with people who have fever blisters. Kissing or sharing cups, glasses, razors, towels, toothbrushes and other objects that a person with a fever blister used can spread the herpes virus.

To help prevent the spread of fever blisters in children, don’t let children share toys that others have put in their mouths and be sure to clean their toys occasionally with a natural disinfectant like lemon essential oil. Children should avoid close contact if one has a fever blister until it begins to scab over.

To Boost Your Immune System:

11. Probiotic Foods

Probiotic foods like yogurt, apple cider vinegar, kimchi, sauerkraut, kefir and natto work to boost the immune system and promote detoxification. (16)

12. Echinacea Tea

Echinacea is a powerful immune system stimulator that can provide significant therapeutic value, even when trying to fight a virus like herpes simplex. This is especially true for people with a weakened immune system. (17) To boost your immune system and prevent an outbreak, drink echinacea tea throughout the week — it helps to reduce inflammation and alleviate pain too, so don’t stop drinking it if a fever blister does develop.

13. Raw Garlic

Raw garlic has antiviral, antifungal and antimicrobial properties that can help to boost your immune system and fight fever blister outbreaks. The World Health Organization recommends a daily dose of 2–3 grams (about one clove) of fresh garlic for adults. (18) Apply it directly to a fever blister to reduce swelling and speed healing. If you feel a fever blister forming, start using garlic right away to prevent it from developing completely.

14. Oregano Essential Oil

Oregano oil is known for its healing and immune-boosting properties. It naturally fights infections due to its antiviral properties. Studies show oregano oil can make it difficult for the virus to infect a person. (19)

15. Tea Tree Oil

A 2001 study conducted in Germany found that tea tree oil has antiviral effects when used against herpes simplex virus-1 and 2. (20) When you feel a fever blister developing, simply add 1–2 drops of tea tree oil to a clean cotton ball and apply it directly to the blister.

Fever Blister Precautions

If your fever blister does not go away within 10 days or you think that you have an infection, consult your doctor. It is important to take precautions when you have an active fever blister to prevent the spread of the virus. Herpes simplex virus can spread easily when the sore is present.

Final Thoughts 

  • The herpes simplex virus causes fever blisters. They are red, swollen and painful blisters that usually develop on the edge of the lips.
  • Until a fever blister forms a crust or scab, it is extremely contagious, which is why it’s such a common ailment.
  • Natural fever blister remedies include using essential oils, aloe vera, zinc and L-lysine and avoiding direct sunlight and reducing contact with a person with a fever blister until it scabs over.

More Health