Most mouth sores heal on their own within 10 to 14 days, but the right combination of home care and over-the-counter treatments can cut down on pain and speed that process along. The approach depends on what type of sore you’re dealing with, how severe it is, and whether something in your diet or daily routine keeps triggering new ones.
Identify What You’re Dealing With
The two most common mouth sores look and behave differently, and treating them effectively starts with telling them apart.
Canker sores appear inside the mouth, usually on the inner cheeks, lips, or tongue. They look like round white or yellow sores with a red border. They’re not contagious, and their exact cause isn’t fully understood, though stress, minor injuries (like biting your cheek), smoking, and nutritional deficiencies can trigger them.
Cold sores show up on the outside of the mouth, around the lips. They start as clusters of small, fluid-filled blisters and are caused by the herpes simplex virus (usually type 1). Unlike canker sores, cold sores are contagious and require antiviral treatment rather than the approaches described below. If your sore is on the outer lip and started as a blister, you’re dealing with a cold sore and should look into antiviral options from your doctor or pharmacist.
The rest of this article focuses on canker sores and other sores inside the mouth, since those are what most people are trying to manage at home.
Salt Water Rinse: The First Step
A salt water rinse is the simplest and most widely recommended starting point. Mix 1 teaspoon of salt into 8 ounces of warm water until it fully dissolves, then swish gently for 30 seconds and spit. If that concentration stings too much, cut the salt to half a teaspoon. Research has found that rinses in the 0.9% to 1.8% salt range promote gum health and tissue recovery.
You can repeat this several times a day, especially after meals. It helps keep the sore clean, reduces bacteria around the wound, and draws fluid out of inflamed tissue to bring down swelling. It won’t eliminate the sore overnight, but it creates better conditions for healing.
Over-the-Counter Pain Relief
When a canker sore makes eating or talking miserable, topical numbing products containing benzocaine (sold under brand names like Orajel and Anbesol) can provide temporary relief. You apply them directly to the sore, and they numb the area within minutes. Reapply as directed on the packaging, typically every few hours.
Another effective option is a hydrogen peroxide dab. Mix equal parts water and hydrogen peroxide, apply to the sore with a cotton swab (don’t swallow it), then follow up by dabbing a small amount of milk of magnesia on top. You can do this up to four times a day. The peroxide helps clean the sore while the milk of magnesia coats and protects it.
Alcohol-free mouth rinses can also help. Avoid rinses that contain alcohol, which will sting and irritate the sore further.
Honey as a Healing Agent
Applying honey directly to a mouth sore isn’t just a folk remedy. In a randomized controlled trial studying oral sores in children undergoing chemotherapy, those treated with Manuka honey had significantly less severe sores and less pain compared to both an olive oil group and a control group receiving standard care. While that study focused on chemotherapy-related sores, the anti-inflammatory and wound-healing properties of honey apply broadly. Dab a small amount of Manuka honey onto the sore a few times a day, letting it sit as long as you can before eating or drinking.
What Triggers Recurring Sores
If you get canker sores frequently, something may be feeding the cycle. Three common culprits are worth investigating.
Nutritional Deficiencies
Vitamin B12 deficiency is strongly linked to recurrent mouth ulcers. In one study, over 50% of patients with recurring canker sores were deficient in B12, compared to none in the control group. Low levels of folate and iron have also been associated with repeated outbreaks. If your sores keep coming back, it’s worth asking your doctor to check these levels with a simple blood test. Foods rich in B12 include meat, fish, eggs, and dairy. Folate is found in leafy greens, beans, and fortified grains.
Your Toothpaste
Sodium lauryl sulfate (SLS) is a foaming agent found in most toothpastes. Some people find that SLS irritates their oral tissue, worsens existing sores, or even triggers new ones. Switching to an SLS-free toothpaste is a low-risk change that’s worth trying if you deal with frequent ulcers. Several brands market SLS-free options specifically for sensitive mouths.
Physical Irritation and Stress
Biting the inside of your cheek, rough dental work, poorly fitting braces or dentures, and even aggressive brushing can all trigger canker sores in susceptible people. Stress is another well-documented trigger. You may notice outbreaks clustering around high-pressure periods at work or school. While you can’t always avoid stress, recognizing the pattern helps you start treatment earlier.
When Minor Sores Become Major Ones
Not all canker sores are equal. Minor canker sores, which account for the majority of cases, typically heal within 10 to 14 days without scarring. Major canker sores are larger, deeper, and significantly more painful. These can take up to 6 weeks to heal and may leave scars.
For major or especially painful sores, your doctor or dentist can prescribe a topical steroid paste. These prescription treatments reduce inflammation and shorten the duration of each episode, though they don’t prevent future outbreaks. They’re typically reserved for sores that are large, unusually painful, or interfering with your ability to eat.
Sores That Don’t Heal: When to Pay Attention
A mouth sore that hasn’t improved after 2 to 3 weeks, or hasn’t fully resolved within 4 weeks, needs professional evaluation. The Oral Cancer Foundation recommends that any oral lesion persisting beyond 2 to 4 weeks be referred to a specialist for a definitive diagnosis. This doesn’t mean every lingering sore is cancer, but any sore that doesn’t respond to normal treatment should be examined and potentially biopsied to rule out something more serious. This is especially true if the sore is painless, has hardened edges, or is accompanied by unexplained weight loss or difficulty swallowing.
A Practical Healing Routine
For a typical canker sore, a reasonable daily approach looks like this: rinse with salt water after meals and before bed. Apply a numbing product like benzocaine before eating if the sore is in a spot that makes chewing painful. Between meals, dab honey on the sore or use the hydrogen peroxide and milk of magnesia method up to four times daily. Avoid spicy, acidic, or crunchy foods that scrape against the sore. Stick with soft, cool foods when pain is at its worst.
Most sores will feel noticeably better within 4 to 5 days and fully resolve within two weeks. If you’re getting canker sores more than a few times a year, focus on the triggers: check your B12 and iron levels, switch to SLS-free toothpaste, and track whether stress or physical irritation lines up with your outbreaks. Addressing the root cause is the only reliable way to reduce how often they come back.