How to Get Rid of a Canker Sore in 24 Hours: 7 Relief Tips

May 31, 2024 | 7 min read

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Canker sores, or aphthous ulcers, are painful ulcers inside the mouth. This article provides effective strategies on how to get rid of a canker sore in 24 hours using over-the-counter treatments and home remedies like saltwater rinses, honey, and coconut oil. 

Follow these tips for quick relief and faster healing.

how to get rid of a canker sore in 24 hours

What are Canker Sores?

Canker sores, also known as aphthous ulcers, are small, painful ulcers that form inside the mouth. They often appear on the soft tissues such as the inside of the lips, cheeks, or gums. Unlike cold sores, canker sores are not contagious and do not appear on the lips' exterior. These ulcers can make eating, talking, and maintaining oral hygiene uncomfortable.

Canker sores


Canker sores come in three main types, each varying in size, number, and severity:

  • Minor Canker Sores: These are the most common type. They are small, usually just a few millimeters in size, and typically heal on their own within one to two weeks. Minor canker sores are often round or oval with a red edge.
  • Major Canker Sores: Less common than minor ones, major canker sores are larger and deeper. They can be more painful and take longer to heal, sometimes up to six weeks. These sores can leave scars.
  • Herpetiform Canker Sores: This type is rare and consists of clusters of tiny ulcers, often numbering 10 to 100. Despite their name, herpetiform canker sores are not caused by the herpes virus. They can merge to form a large, irregularly shaped sore and usually heal within two weeks without scarring.


According to the Cleveland Clinic publication, the exact cause of canker sores remains unclear, but several factors are known to trigger their development:

  • Stress: Emotional stress is a significant trigger for many people. Stress can weaken the immune system, making it easier for canker sores to develop.
  • Minor Injuries: Simple injuries like accidentally biting the inside of your cheek, brushing too hard, or irritation from dental work can lead to canker sores.
  • Vitamin Deficiencies: A lack of certain vitamins and minerals, particularly B12, zinc, iron, and folic acid, can increase the likelihood of developing canker sores.
  • Acidic Foods: Eating foods high in acidity, such as citrus fruits and tomatoes, can trigger or worsen canker sores.
  • Hormonal Changes: Hormonal fluctuations, particularly in women, can contribute to the development of canker sores.
  • Autoimmune Disorders: Conditions that affect the immune system, such as lupus or inflammatory bowel diseases, can cause recurrent canker sores.
  • Medications: Some medications, particularly nonsteroidal anti-inflammatory drugs (NSAIDs) and beta-blockers, can contribute to canker sore development.

Symptoms and Appearance

  • Round or Oval Ulcers: Typically white or yellow with a red border.
  • Burning or Tingling Sensation: Often felt before the sore appears.
  • Swelling: The area around the sore may be swollen.
  • Pain: The primary symptom, which can be intense, especially when eating or talking.

If you’re unsure about your symptoms, consider using an online tool like the Symptom Checker to identify potential health issues, but remember, always consult a professional for medical advice.

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Immediate Relief: OTC Treatments

  • Topical Anesthetics: Products containing lidocaine are commonly used to numb the sore area, providing temporary pain relief. Applying these products directly to the sore can help reduce discomfort, making it easier to eat and talk.
  • Corticosteroids: These are used to reduce inflammation and pain. Corticosteroid gels or ointments can be applied directly to the sore to decrease swelling and speed up the healing process.
  • NSAIDs: Nonsteroidal anti-inflammatory drugs can be used for pain relief. They reduce inflammation and provide temporary relief from canker sore discomfort. However, it's essential to follow the usage instructions carefully to avoid potential side effects.
  • Mouthwashes: Specific mouthwashes designed for canker sores can help with pain relief and healing. These often contain ingredients that soothe the sore, reduce inflammation, and prevent infection. Look for mouthwashes that do not contain alcohol, as alcohol can irritate the sore.

Home Remedies for Quick Relief

1. Saltwater Rinse

A saltwater rinse is a simple and effective home remedy for canker sores. It helps reduce inflammation and bacteria in the mouth, promoting faster healing.

The saltwater rinse can be a bit uncomfortable due to its stinging effect, but it’s effective in cleaning the sore and reducing swelling.

2. Baking Soda Rinse

Baking soda helps restore pH balance and reduce inflammation in the mouth, aiding in the healing of canker sores.


  • Neutralizes acids in the mouth that can irritate the sore.
  • Reduces inflammation and bacteria.
  • Promotes a more alkaline environment, which can speed up healing.

Instructions for Salt/ Baking Soda Rinse

  • Dissolve 1 teaspoon of baking soda in 1/2 cup of warm water or 1 teaspoon of salt in 1 cup of warm water.
  • Stir well to ensure the baking soda/salt is fully dissolved.
  • Swish the solution in your mouth for 15-30 seconds.
  • Spit it out and rinse your mouth with plain water.
  • Repeat this rinse 3-4 times a day.

3. Alum Powder

Alum powder has astringent properties that can help shrink and dry out canker sores.


Mix a small amount of alum powder with a few drops of water to create a paste.

  1. Apply the paste directly to the canker sore.
  2. Leave it on for at least 1 minute.
  3. Rinse your mouth thoroughly with water.
  4. Repeat daily until the sore heals.

Alum powder may cause a temporary stinging sensation but is effective in reducing the size and pain of canker sores.

4. Honey

Honey is known for its antibacterial and anti-inflammatory properties, making it an excellent remedy for canker sores.


  1. Use a clean cotton swab to apply a small amount of honey directly to the canker sore.
  2. Reapply honey 3-4 times a day, especially after meals and before bed.


  • Reduces pain and inflammation.
  • Helps prevent secondary infections due to its antibacterial properties.
  • Promotes faster healing of the sore.

For best results, use raw, unpasteurized honey, as it retains more of its natural healing properties.

5. Coconut Oil

Coconut oil has antimicrobial and anti-inflammatory properties that can help treat canker sores and reduce pain.


  1. Apply a small amount of coconut oil directly to the canker sore using a cotton swab.
  2. Reapply several times a day, especially after eating and before bedtime.


  • Soothes the sore and reduces inflammation.
  • Helps prevent infection.
  • Promotes faster healing.

Coconut oil can also be used as a mouth rinse. Swish a tablespoon of coconut oil in your mouth for 10-15 minutes (oil pulling), then spit it out and rinse with warm water.

6. Hydrogen Peroxide

Hydrogen peroxide is an antiseptic that can help clean canker sores and reduce bacteria in the mouth.


  1. Dilute a 3% hydrogen peroxide solution with equal parts water.
  2. Dip a cotton swab or cotton ball into the mixture.
  3. Apply it directly to the canker sore.
  4. Alternatively, you can use the solution as a mouth rinse. Swish it around your mouth for about 30 seconds, then spit it out.
  5. Repeat 2-3 times a day.

Safety Tips

  • Do not swallow hydrogen peroxide.
  • Ensure proper dilution to avoid irritation.

7. Yogurt

Yogurt contains live probiotic cultures that can help balance the bacteria in your mouth and support the healing process.


  1. Eat at least one cup of plain, unsweetened yogurt daily.
  2. You can also apply yogurt directly to the canker sore using a cotton swab.


  • Probiotics help maintain a healthy balance of bacteria in the mouth.
  • Reduces inflammation and pain.
  • Supports overall oral health and immune function.

Additional Remedies for Faster Healing

Chamomile Compress

Chamomile has anti-inflammatory and antiseptic properties that can soothe canker sores and promote healing.


  1. Steep a chamomile tea bag in hot water for 1-2 minutes.
  2. Let the tea bag cool to a comfortable temperature.
  3. Apply the tea bag directly to the canker sore for 5-10 minutes.
  4. Repeat this process 2-3 times a day.


  • Reduces pain and inflammation.
  • Soothes the sore and accelerates healing.

Echinacea and Sage

Echinacea and sage have natural healing properties that can help with canker sores.

Echinacea Usage

  • Mix 1 teaspoon of liquid echinacea with a small amount of warm water.
  • Swish the mixture in your mouth for 1-2 minutes.
  • Spit it out. Repeat 2-3 times a day.

Sage Usage

  • Steep 1-2 teaspoons of dried sage leaves in boiling water for 5 minutes.
  • Let the solution cool.
  • Use it as a mouth rinse, swishing for 1-2 minutes.
  • Repeat 2-3 times a day.


  • Echinacea boosts the immune system and helps heal sores faster.
  • Sage has antibacterial, anti-inflammatory, and antiseptic properties.

DGL Mouthwash

Deglycyrrhizinated licorice (DGL) is known for its anti-inflammatory properties and can be effective for canker sores.


  • Reduces pain and inflammation.
  • Helps speed up the healing process.

Apple Cider Vinegar

Apple cider vinegar (ACV) has antibacterial properties but should be used cautiously due to its acidity.


  1. Dilute 1 teaspoon of apple cider vinegar in 1 cup of water.
  2. Swish the mixture in your mouth for 30 seconds to 1 minute.
  3. Spit it out and rinse your mouth thoroughly with water.
  4. Repeat once daily.

Cautionary Advice

  • Do not apply undiluted ACV directly to the sore as it can cause irritation.
  • Always rinse your mouth after using ACV to protect your tooth enamel.

Using these home remedies can provide quick relief from canker sores and promote faster healing.

When to Seek Medical Help

  • Persistent Sores: If a canker sore does not heal within two weeks.
  • Severe Pain: If the pain from the canker sore is intolerable and interferes with daily activities like eating and speaking.
  • Frequent Recurrence: If you frequently develop new sores before the old ones heal.
  • Unusually Large Sores: Sores that are larger than one centimeter in diameter.
  • Multiple Sores: If you have several canker sores at once.
  • Fever: A fever accompanying a canker sore might indicate an infection or another underlying condition.
  • Difficulty Eating or Drinking: If the sore makes it hard to eat or drink.

Frequently Asked Questions

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Canker sores can be painful, but understanding their causes and treatments helps manage them effectively. Over-the-counter treatments like topical anesthetics, corticosteroids, NSAIDs, and specific mouthwashes provide quick relief. Home remedies such as saltwater rinses, baking soda rinses, honey, coconut oil, and chamomile compresses are also effective.

Seek medical help if sores persist, are unusually large, or cause severe pain or fever. Good oral hygiene and stress management can prevent future outbreaks. 

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