Most mouth sores heal on their own within one to two weeks, but the right combination of topical treatments, rinses, and dietary adjustments can cut that timeline noticeably shorter. What works best depends on the type of sore you’re dealing with, since canker sores (inside the mouth) and cold sores (on or around the lips) respond to completely different treatments.
Canker Sores vs. Cold Sores: Know Which You Have
This matters because the wrong treatment won’t help. Canker sores appear inside the mouth on soft tissue: the inner cheeks, gums, tongue, or soft palate. They’re small, round, usually white or yellowish with a red border, and they’re not contagious. Cold sores appear on or around the lips, start as a cluster of fluid-filled blisters, and are caused by the herpes simplex virus.
Cold sores require prescription antiviral medications, either as a topical cream or an oral pill. Starting antiviral treatment at the first sign of tingling can shorten an outbreak by several days. Over-the-counter numbing gels won’t speed healing of a cold sore, they only mask pain. If you’re dealing with cold sores, the most effective thing you can do is get a prescription early.
Canker sores respond to a wider range of home and over-the-counter treatments, and that’s where most of the practical advice below applies.
Rinses That Actually Help
A saltwater or baking soda rinse is the simplest starting point, and it works. Salt draws fluid from inflamed tissue to reduce swelling, while baking soda neutralizes acids in the mouth that irritate open sores. Memorial Sloan Kettering Cancer Center recommends mixing 1 teaspoon of salt and 1 teaspoon of baking soda into 1 quart (4 cups) of water. You can also use just salt or just baking soda at the same ratio. Swish gently for 30 seconds and spit. Repeat three to four times a day, especially after meals.
Over-the-counter antiseptic mouth rinses containing hydrogen peroxide (typically diluted to 1.5% or 3%) can help prevent secondary infection of the sore and support faster healing. Look for products labeled for mouth sore care rather than standard mouthwash, and avoid any rinse containing alcohol, which will sting and may further irritate damaged tissue.
Topical Treatments Worth Trying
Benzocaine gels, available over the counter at 20% concentration in products like Orajel, numb pain on contact and create a temporary protective layer over the sore. Apply a small amount directly to the ulcer up to four times a day. The pain relief is immediate but short-lived, typically lasting 20 to 30 minutes. While benzocaine doesn’t accelerate tissue repair directly, reducing pain makes it easier to eat, drink, and keep up with oral hygiene, all of which support healing.
For canker sores that are large or especially painful, dentists sometimes prescribe a corticosteroid paste that reduces inflammation at the site. These prescription options are worth asking about if you get canker sores frequently or if a current one is making it hard to eat.
Honey as a Topical Treatment
Raw honey applied directly to a canker sore is surprisingly effective. In a clinical comparison, minor canker sores treated with honey dressings shrank from an average of 3.5 mm to essentially zero within three days, performing as well as a prescription corticosteroid paste. Honey has natural antibacterial and anti-inflammatory properties, and its thick consistency helps it stay on the sore. Dab a small amount onto the ulcer two to three times daily, ideally after rinsing your mouth. Use raw, unprocessed honey for the best results.
Stop Irritating the Sore
What you avoid can matter as much as what you apply. Spicy foods, acidic fruits (oranges, tomatoes, pineapple), crunchy chips, and very hot beverages all aggravate open sores and slow healing. Stick to soft, bland, room-temperature foods while a sore is active.
Your toothpaste may also be a factor, especially if you get canker sores repeatedly. Sodium lauryl sulfate (SLS), the foaming agent in most toothpastes, is a known irritant to oral mucosa. In one clinical study, participants who switched from an SLS-containing toothpaste to an SLS-free one saw their number of canker sores drop from an average of 14.3 to just 5.1 over the study period. That’s roughly a 64% reduction. Brands like Sensodyne, Biotene, and some versions of Tom’s of Maine are SLS-free. If you’re prone to recurring sores, this is one of the easiest changes you can make.
Nutrients That Support Mouth Healing
Recurring canker sores are sometimes linked to nutritional deficiencies, particularly iron, B vitamins, zinc, and folate. If your sores keep coming back, it’s worth checking whether your diet is falling short in any of these areas.
Vitamin B12 plays a direct role in maintaining healthy oral mucosa, and even a mild deficiency can increase vulnerability to ulcers. A B-complex supplement providing a range of B vitamins, along with 15 mg of zinc daily, has been used in clinical settings to support oral tissue repair. You don’t need mega-doses. A standard B-complex and a low-dose zinc supplement, taken consistently for at least a month, can make a difference if deficiency was contributing to the problem. A simple blood test from your doctor can confirm whether a deficiency is at play.
Professional Treatments for Stubborn Sores
If a canker sore is large (over 1 cm), unusually painful, or not responding to home care within a week, your dentist has tools that go beyond what’s available over the counter. Low-level laser therapy is one option that’s gaining traction. It works by stimulating cell repair and blood flow at the wound site while also reducing pain and swelling. Studies show it significantly accelerates ulcer closure, and many patients report immediate pain relief after a single session.
Dentists can also apply chemical cauterizing agents directly to the sore, which destroys the damaged nerve endings (stopping pain almost instantly) and creates conditions for faster tissue regeneration. It stings for a moment during application but provides lasting relief.
When a Mouth Sore Needs Medical Attention
Any sore that hasn’t healed within two weeks should be evaluated by a dentist or doctor. Most mouth sores are harmless, but non-healing lesions can occasionally signal something more serious, including oral cancer. Specific warning signs include patches that are unusually white, red, or a mix of both; a sore that becomes hard, raised, or develops a rough texture; and any lesion that bleeds without clear cause. Pain alone isn’t a reliable indicator, since not all concerning lesions hurt. The two-week threshold is the key benchmark. If a sore lingers past that point, get it looked at.