Most mouth sores heal on their own within 10 to 14 days, but the right care can reduce pain and speed that timeline. What you should do depends on the type of sore you’re dealing with, since canker sores and cold sores have different causes and respond to different treatments.
Identify What Kind of Sore You Have
The two most common types of mouth sores are canker sores and cold sores, and they behave differently. Canker sores (aphthous ulcers) appear inside the mouth, usually on the inner cheeks, lips, or tongue. They look like a single round white or yellow sore with a red border. They’re not contagious. No one knows exactly what causes them, but they can be triggered by injury (biting your cheek, a sharp chip), stress, smoking, or deficiencies in iron, vitamin B12, or folic acid.
Cold sores (fever blisters) show up on the outside of the mouth, typically along the border of the lips. They appear as clusters of small, painful, fluid-filled blisters and are caused by herpes simplex virus type 1 (HSV-1). They are contagious, especially when the blisters are open. Knowing which type you’re dealing with matters because the treatments are different.
Saltwater Rinses and Basic Home Care
For canker sores and minor irritation sores, a simple saltwater rinse is one of the most effective first steps. Mix 1 teaspoon of salt into 8 ounces of warm water and swish gently for 30 seconds before spitting it out. If your mouth is especially tender and the rinse stings, drop to half a teaspoon of salt for the first day or two. You can repeat this several times a day, particularly after eating, to keep the area clean and reduce bacteria around the sore.
Beyond rinsing, a few practical habits help sores heal faster. Avoid spicy, acidic, or rough-textured foods that scrape or sting the area. Citrus, tomato sauce, chips, and crusty bread are common irritants. Stick to softer, cooler foods while the sore is at its worst. Drinking through a straw can help liquids bypass a sore on the inner lip or cheek.
Over-the-Counter Pain Relief
Topical numbing products containing benzocaine or lidocaine can take the edge off mouth sore pain. In a controlled trial, a 1% lidocaine cream applied directly to canker sores or oral tissue injuries reduced pain intensity significantly more than a placebo. These products work by temporarily numbing the nerve endings at the surface. You’ll find them in gels, creams, and patches at most pharmacies. Apply a small amount directly to the sore before meals or whenever pain is interfering with eating or talking.
For canker sores that are particularly large or painful, topical corticosteroid pastes (available over the counter or by prescription) can reduce inflammation and may shorten healing time. These are most effective when applied early, ideally as soon as you notice the sore forming. A thin layer applied to a dry sore before bed gives the medication the longest contact time.
Cold sores require a different approach. Over-the-counter antiviral creams containing docosanol can shorten an outbreak if applied at the first sign of tingling, before blisters fully form. For frequent or severe cold sore outbreaks, a doctor can prescribe oral antiviral medication that works more aggressively.
Honey as a Healing Aid
Honey has genuine evidence behind it for mouth sores. It creates a protective barrier over the ulcer, keeps the area moist, and has natural antibacterial and anti-inflammatory properties. In one clinical observation, children with chemotherapy-related mouth sores who used a manuka honey paste experienced healing within three days. While most studies have focused on medically-induced mouth sores, the mechanism applies to everyday canker sores as well. Dab a small amount of raw honey (manuka if available) directly onto the sore a few times a day. It will sting briefly, then coat the area.
Check Your Toothpaste
If you get canker sores repeatedly, your toothpaste may be contributing. Many toothpastes contain sodium lauryl sulfate (SLS), a foaming agent that can irritate the delicate tissue inside the mouth. Research has shown that SLS-containing toothpaste can increase the frequency of recurrent mouth ulcers in people with sensitive oral tissue. Switching to an SLS-free toothpaste is a low-effort change that may noticeably reduce how often sores appear. Several major brands sell SLS-free versions, typically marketed for sensitive mouths.
Nutritional Deficiencies and Recurring Sores
People who get canker sores over and over again are significantly more likely to be deficient in iron, vitamin B12, and folic acid compared to people who rarely get them. These nutrients play key roles in maintaining healthy mucous membranes inside the mouth. If your sores keep coming back, especially more than three or four times a year, it’s worth checking your intake of these nutrients.
Iron is found in red meat, lentils, spinach, and fortified cereals. Vitamin B12 comes primarily from animal products like meat, fish, eggs, and dairy, which makes vegetarians and vegans particularly vulnerable to deficiency. Folic acid is abundant in leafy greens, beans, and citrus fruits. If dietary changes don’t help, a blood test can reveal whether supplementation is warranted.
How Long Healing Takes
Minor canker sores, the small round ones most people get, typically heal within 10 to 14 days without scarring. Major canker sores, which are larger and deeper, can take up to six weeks to heal and may leave a scar. Most people deal exclusively with the minor variety.
Cold sores generally run their course in 7 to 10 days. The blisters break open, crust over, and gradually disappear. Antiviral treatment started early can shave a day or two off this timeline. During healing, avoid picking at the crust, which slows the process and increases the risk of spreading the virus or developing a secondary infection.
Warning Signs That Need Attention
A sore that hasn’t healed after two weeks deserves professional evaluation. The two-week mark is the standard threshold clinicians use to distinguish routine sores from something that may need a biopsy. Sores related to minor infection, inflammation, or local trauma typically resolve within that window.
Certain features raise concern regardless of timing. A sore that is red and white in color, feels hard or fixed to deeper tissue, bleeds easily, or grows rapidly could indicate something more serious, including oral cancer. Unexplained pigmented spots that are new or changing also warrant evaluation. This doesn’t mean every lingering sore is dangerous, but persistent sores that don’t follow the normal healing pattern should be looked at by a dentist or doctor.