How to Get Rid of a Canker Sore Fast: 5 Methods That Actually Work

If you have a canker sore right now, you want it gone. Not managed. Not numbed for an hour. Gone.

Most canker sores (aphthous ulcers) heal on their own in 7 to 14 days. But you don't have to wait that long. The right treatment — applied early — can cut healing time significantly and stop the pain immediately.

Here are five methods ranked by how fast they actually work, based on mechanism of action and what users consistently report.

1. Chemical Cautery (Fastest — Single Application)

Chemical cautery is the fastest way to eliminate a canker sore. It works by sealing the ulcer in a single application — removing damaged tissue, killing bacteria, and forming a protective barrier over the wound. Pain relief is immediate and lasting because the barrier covers exposed nerve endings physically, not chemically.

ORALMEDIC is the only over-the-counter chemical cautery treatment available in Canada. It uses patented HYBENX Desiccation Shock Technology to treat canker sores in one use. Most users report complete healing within 3 to 5 days.

How to use it:

1. Dry the ulcer thoroughly with the included cotton bud (this is the most important step)
2. Snap the coloured ring on the applicator to release the gel
3. Roll the applicator across the entire ulcer surface for 5 to 10 seconds
4. Rinse your mouth with water and spit
5. Wait 30 minutes before eating or drinking

What to expect: A brief stinging sensation (5 to 15 seconds) during application — this is the active ingredient working on damaged tissue. The sting stops once the protective barrier forms. After that, pain relief is immediate and the ulcer is sealed.

Best for: Severe or painful canker sores, recurring ulcers, anyone tired of reapplying numbing gels multiple times a day.

2. Salt Water Rinse (Immediate Relief — Promotes Healing)

A warm salt water rinse is the most accessible canker sore remedy and one that dentists consistently recommend. Salt draws fluid from the ulcer through osmosis, which reduces swelling, and creates an environment that's hostile to bacteria.

How to make it:

• Dissolve 1 teaspoon of table salt in 250 mL (1 cup) of warm water
• Swish around your mouth for 30 to 60 seconds, concentrating on the sore
• Spit — do not swallow
• Repeat 3 to 4 times daily

What to expect: Temporary stinging during the rinse, followed by reduced pain and swelling. This won't eliminate the canker sore quickly, but it supports faster natural healing and keeps the area clean.

Best for: Mild canker sores, pain management between meals, and as a complement to other treatments.

3. Over-the-Counter Numbing Gels (Temporary Pain Relief)

Benzocaine-based gels like Orajel and Anbesol are the most widely used canker sore treatments in Canada. They work by temporarily blocking nerve signals at the application site, numbing the pain for 1 to 2 hours.

How to use them:

• Dry the area and apply a small amount of gel directly to the canker sore
• Reapply every 3 to 4 hours as needed (up to 4 times daily)
• Avoid eating or drinking for 15 to 30 minutes after application

What to expect: Quick pain relief (within minutes) that lasts 1 to 2 hours before wearing off. The ulcer itself heals at its own pace — benzocaine does not speed up healing.

Important note: Benzocaine carries an FDA warning about methemoglobinemia, a rare but serious condition. It should not be used on children under 2 years of age.

Best for: Mild to moderate pain relief when you need temporary numbing — especially before meals or sleep.

For a detailed comparison of benzocaine gels vs chemical cautery, read our guide on benzocaine for canker sores.

4. Hydrogen Peroxide Rinse (Antiseptic — Promotes Healing)

A diluted hydrogen peroxide rinse helps clean the canker sore and reduce bacteria in the mouth. It works as a mild antiseptic and debriding agent, which can support faster healing.

How to use it:

• Mix equal parts 3% hydrogen peroxide and water (1:1 ratio)
• Dab directly onto the canker sore with a cotton swab, or swish gently for 30 seconds
• Spit thoroughly — do not swallow
• Use once or twice daily

What to expect: Mild bubbling or fizzing on the ulcer (this is normal — it's oxygen being released as the peroxide reacts with tissue). Some temporary stinging. Regular use may shorten healing time modestly.

Best for: Keeping the ulcer clean and reducing infection risk, particularly for larger sores.

5. Anti-Inflammatory Products (Pain + Swelling Reduction)

Anti-inflammatory gels and rinses help reduce the swelling and inflammation around the canker sore, which is a major contributor to pain. Options include:

• Benzydamine rinse (Tantum) — an anti-inflammatory mouthwash available in Canadian pharmacies. Rinse and gargle as directed. Provides both anti-inflammatory and mild analgesic effects.
• Corticosteroid paste (prescription) — your doctor or dentist may prescribe triamcinolone acetonide paste for severe or recurring ulcers. Apply directly to the sore to reduce inflammation.
• Ibuprofen (oral) — while not a topical treatment, over-the-counter ibuprofen reduces oral inflammation and pain systemically. Useful when a canker sore is making eating difficult.

Best for: Large, inflamed canker sores and situations where swelling is the primary issue.

Which Method Should You Choose?

The right approach depends on how severe your canker sore is and what you're trying to achieve:

You can also combine methods. A salt water rinse to keep the area clean plus a treatment like ORALMEDIC to seal the ulcer is a practical combination.

Tips for Faster Healing

Regardless of which treatment you choose, these habits help canker sores heal faster:

• Avoid irritating foods — citrus, spicy foods, chips, and hard-edged foods will aggravate the sore. Read our guide on canker sores and diet for a full breakdown.
• Use a soft-bristled toothbrush — hard bristles can traumatize the sore and delay healing.
• Switch to SLS-free toothpaste — sodium lauryl sulfate (SLS) in most toothpastes irritates oral tissue. Learn more about this and other triggers in what causes canker sores.
• Treat early — the sooner you treat a canker sore, the faster it heals. Don't wait for it to get worse.
• Stay hydrated — a dry mouth slows healing and increases discomfort.

When to See a Doctor

Most canker sores are harmless and heal within 2 weeks. See a healthcare provider if:

• The sore is larger than 1 cm
• It hasn't healed after 2 weeks
• You get canker sores very frequently (more than 3-4 per month)
• The sore comes with fever, rash, or difficulty swallowing
• You have trouble eating or drinking due to pain

Persistent or unusually severe canker sores can sometimes indicate an underlying condition. Visit our FAQ for answers to common questions, or contact us if you need help.