Most canker sores heal on their own within 10 to 14 days, but the right combination of treatments can cut that time shorter and make the wait far less painful. What works best depends on severity: minor sores respond well to over-the-counter products and home remedies, while larger or recurring sores may need a prescription or an in-office procedure.
Saltwater and Honey: Simple Remedies That Work
A warm saltwater rinse (about half a teaspoon of salt in a cup of water, swished for 30 seconds) is the most accessible first step. Salt draws fluid out of swollen tissue, temporarily reducing inflammation and helping keep the area clean. You can repeat this several times a day, especially after meals.
Honey is worth trying if you want something with more evidence behind it. In a randomized clinical trial published in the Brazilian Journal of Oral Sciences, a honey-based spray healed canker sores in about 5 days on average, with pain dropping to near zero by day 2. That performance matched a prescription steroid ointment (triamcinolone) almost exactly. Dabbing a small amount of raw honey directly on the sore a few times a day provides a protective coating and has mild antibacterial properties. It stings briefly on contact, then soothes.
Milk of magnesia applied with a cotton swab can also help by coating the ulcer and neutralizing the acidic environment in your mouth that irritates exposed tissue. Some people alternate between a saltwater rinse and a dab of milk of magnesia throughout the day.
Over-the-Counter Numbing Gels and Patches
Benzocaine gels (sold as Orajel, Anbesol, and similar brands) are the most common OTC option. Benzocaine is a local anesthetic that blocks nerve signals in the tissue, numbing the sore within a minute or two. The relief is temporary, usually lasting 30 to 60 minutes, but it can make eating and drinking far more manageable. Apply a small amount directly to the sore with a clean finger or cotton swab.
Adhesive patches designed specifically for canker sores take a different approach. Rather than numbing the area, they form a physical barrier over the ulcer, shielding it from food, drinks, and the constant friction of your tongue and cheeks. Some patches also contain a mild medication. These tend to work best on sores in easy-to-reach spots like the inside of your lip.
Prescription Options for Stubborn Sores
If OTC products aren’t enough, a prescription corticosteroid paste like triamcinolone acetonide can reduce the inflammation driving the pain and swelling. You press a small amount onto the sore with a cotton swab after meals and at bedtime to form a thin protective film. The key is pressing, not rubbing. Rubbing makes the paste crumbly and ineffective.
For sores that are especially painful or slow to heal, your dentist or doctor may offer chemical cautery. Debacterol is a topical solution that chemically seals the sore in a single application and can reduce healing time to about a week. Silver nitrate, another cautery option, hasn’t been shown to speed healing but does provide significant pain relief. Both involve a brief, sharp sting during application followed by noticeably less pain afterward.
Laser Treatment: Fast but Less Accessible
Low-level laser therapy is one of the more impressive options if your dentist offers it. A study using a common red laser pen found that a single 30-second treatment increased healing speed by two to six times compared to no treatment. Sores that normally took 6 to 10 days to heal were comfortable and visibly closing within 1 to 2 days after a laser session. The treatment is painless and takes under a minute, but it requires a dental visit, so it’s not practical for every canker sore you get.
Nutritional Gaps That Fuel Recurring Sores
If you get canker sores frequently, the cause may be nutritional rather than local. Deficiencies in vitamin B12, iron, and folate are all linked to recurrent oral ulcers. B12 deficiency in particular can trigger a range of oral problems including recurring ulcers, a burning sensation on the tongue, and inflammation at the corners of the mouth.
You don’t necessarily need to be severely deficient for it to matter. Even borderline-low levels of these nutrients can make your mouth’s lining more fragile and slower to repair. If your sores keep coming back every few weeks, it’s worth asking for a blood panel that includes B12, iron, and folate levels. Correcting a deficiency often reduces or eliminates the cycle of recurring sores entirely.
What Triggers Canker Sores in the First Place
Knowing what sets them off helps you prevent the next one. Common triggers include biting the inside of your cheek, aggressive tooth brushing, sharp edges on dental appliances or braces, and toothpastes containing sodium lauryl sulfate (a foaming agent that irritates the lining of the mouth for some people). Switching to an SLS-free toothpaste is an easy first experiment if you get sores often.
Stress, hormonal shifts, and acidic or spicy foods are also well-established triggers. Some people notice a pattern tied to citrus fruits, tomatoes, or chocolate. Tracking what you ate or what was happening in the days before a sore appears can help you identify your personal triggers over time.
How Long Different Types Take to Heal
Not all canker sores are the same, and the type you have determines a realistic healing timeline. Minor canker sores, the most common kind, are small (under a centimeter) and heal in about 10 to 14 days without treatment. These are what most people are dealing with when they search for relief.
Major canker sores are larger, deeper, and significantly more painful. They can last up to a month and sometimes leave a scar. Herpetiform canker sores are a third, rarer type that appear as clusters of tiny ulcers which can merge into larger, irregular sores. These persist anywhere from 10 to 100 days and make eating and speaking extremely difficult. Both major and herpetiform types generally warrant professional treatment rather than home management alone.
Signs a Canker Sore Needs Medical Attention
Most canker sores are harmless, but certain patterns signal something beyond a routine ulcer. Sores that last longer than two weeks, grow unusually large, or keep recurring before previous ones have healed are worth having evaluated. A high fever alongside mouth sores, pain that doesn’t respond to any self-care, or sores that extend onto the outer border of your lips (which may actually be cold sores, a different condition) also call for a visit. If a sharp tooth edge or dental appliance keeps triggering sores in the same spot, your dentist can smooth or adjust it to break the cycle.