Most mouth sores heal on their own within one to two weeks, but you can speed things along and cut the pain significantly with a few simple treatments. The right approach depends on what type of sore you’re dealing with, since canker sores (inside the mouth) and cold sores (outside, around the lips) have different causes and respond to different remedies.
Identify What You’re Dealing With
The fastest way to tell the difference is location. Canker sores 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, and their exact cause is unknown, though stress, minor injuries (like biting your cheek), and nutritional deficiencies can trigger them.
Cold sores show up on the outside of the mouth, typically around the border of the lips. They appear as a cluster of small, fluid-filled blisters caused by the herpes simplex virus (usually type 1). Unlike canker sores, cold sores are contagious. If your sore is a cold sore, antiviral treatment works best when started within the first 48 hours of symptoms.
Salt Water Rinse: The First Thing to Try
A warm salt water rinse is the simplest and most effective home treatment for canker sores and general mouth irritation. Mix 1 teaspoon of salt into 8 ounces of warm water until it dissolves completely. If that stings too much, drop to half a teaspoon. Swish for 15 to 30 seconds, then spit. You can do this up to four times a day, plus after meals. Salt water reduces bacteria around the sore and draws out fluid from inflamed tissue, which helps with both pain and healing.
Over-the-Counter Pain Relief
Numbing gels containing benzocaine are the go-to for immediate pain relief. Products with 10 to 20 percent benzocaine (like Orajel or Anbesol) work within minutes. In clinical testing, 20 percent benzocaine gel reduced pain for about 87 percent of users within the first 5 to 20 minutes of application, while the 10 percent version helped roughly 81 percent. The relief is temporary, lasting around one to two hours, but it makes eating and drinking much more manageable.
You can also find over-the-counter protective pastes that coat the sore and shield it from further irritation. These are especially useful if the sore is in a spot that keeps rubbing against your teeth.
Honey as a Healing Agent
Applying a small amount of honey directly to a mouth sore is more than a folk remedy. A systematic review of 13 clinical studies found that honey reduced the severity or duration of oral ulcers in 12 of them. In one study, severe mouth sores dropped from 55 percent in the control group to 20 percent in the group using honey. Honey has natural antibacterial properties and creates a moist barrier over the wound that supports tissue repair. Dab a small amount on the sore a few times a day, ideally after rinsing your mouth.
Avoid Foods That Make It Worse
Certain foods don’t cause mouth sores, but they can make existing ones significantly more painful and slow healing. The biggest offenders are acidic foods like citrus fruits, tomatoes, and vinegar-based dressings. Highly salty foods, spicy dishes, and cinnamon flavoring are also common irritants. Even ingredients in toothpaste, mouthwash, candy, and gum can trigger reactions in some people.
Stick to soft, bland, cool foods while your sore heals. Think yogurt, oatmeal, mashed potatoes, and smoothies. Avoiding irritants gives the tissue a chance to repair without being re-injured several times a day.
When a Sore Won’t Heal on Its Own
If your sore hasn’t improved after about a week of home treatment, a dentist or doctor can prescribe a stronger option. Prescription-strength steroid pastes reduce inflammation directly at the sore site and are typically used for stubborn canker sores or ulcers caused by trauma. If there’s no meaningful improvement within two weeks of prescription treatment, your provider will likely want to investigate further.
For severe or recurring cases, some dental offices offer low-level light therapy, which uses targeted LED or laser light to reduce swelling, relieve pain, and speed tissue healing. Sessions take about 5 to 10 minutes and can be done up to five times per week.
Preventing Sores From Coming Back
If you get canker sores regularly, your toothpaste might be part of the problem. Sodium lauryl sulfate (SLS), the foaming agent in most toothpastes, has been shown to increase the frequency of recurrent mouth ulcers. One clinical study found four times fewer soft tissue lesions in people using SLS-free toothpaste compared to a standard formula. Brands like Sensodyne, Biotene, and Verve all make SLS-free options.
Nutritional gaps also play a role. Among people with recurrent canker sores, about 21 percent have iron deficiency, nearly 5 percent are low in vitamin B12, and around 3 percent are deficient in folate. Anemia shows up in roughly 21 percent of recurrent cases. If you’re getting canker sores more than a few times a year, it’s worth having your levels checked through a simple blood test. Correcting a deficiency often reduces or eliminates the cycle entirely.
Signs That Need Professional Attention
Any mouth sore that lasts longer than two weeks without improvement should be evaluated, even after removing obvious irritants like sharp tooth edges or ill-fitting dental work. A sore that’s unusually large, increasingly painful, numb, or accompanied by white or red patches on the gums or tongue may need a biopsy to rule out precancerous changes or oral cancer. Difficulty swallowing or a persistent change in taste alongside a non-healing sore also warrants a closer look.