Most mouth sores heal on their own within one to two weeks, but you can speed up recovery and cut the pain significantly with a few targeted strategies. The right approach depends on the type of sore you’re dealing with, so identifying it is the first step toward relief.
Identify Your Mouth Sore First
The two most common types of mouth sores look and behave differently, and they respond to different treatments.
Canker sores appear inside the mouth as single, round white or yellow sores with a red border. They’re typically small (2 to 3 mm), though larger ones can reach 1 to 3 cm. They don’t have a single known cause but can be triggered by injury to the mouth (biting your cheek, aggressive brushing), stress, smoking, or deficiencies in iron, folic acid, or vitamin B12.
Cold sores (fever blisters) show up on the outside of the mouth, around the lips, as clusters of small fluid-filled blisters. They’re caused by the herpes simplex virus, usually type 1. Because they’re viral, they require antiviral treatment rather than the remedies that work for canker sores.
Other mouth sores can result from chemotherapy, autoimmune conditions, oral thrush, or bacterial infections like strep throat. If your sore doesn’t fit either description above, the treatment plan changes, and a healthcare provider can help sort it out.
Home Remedies That Actually Help
A saltwater rinse is the simplest and most effective first-line treatment. Mix 1 teaspoon of salt into 8 ounces of warm water and swish gently for 30 seconds before spitting. If the rinse stings too much, drop to half a teaspoon of salt for the first day or two. You can rinse several times a day, especially after meals, to keep the area clean. Just avoid overdoing it or swallowing the water, which can dehydrate you.
Honey applied directly to a mouth sore can reduce both pain and lesion size. A clinical trial comparing honey paste to a standard prescription steroid ointment found that honey performed as well or better for pain relief and healing. You can dab a small amount of raw honey onto the sore a few times a day. It forms a protective coating and has natural anti-inflammatory properties.
Avoiding irritants matters just as much as applying remedies. Spicy, acidic, and crunchy foods can aggravate an open sore and slow healing. Stick to soft, cool, or room-temperature foods while you’re recovering.
Over-the-Counter Options
Numbing gels containing benzocaine are widely available at pharmacies and work by temporarily blocking pain signals in the tissue. You apply a small amount directly to the sore, and relief kicks in within minutes. These products won’t speed healing, but they make eating and talking far more comfortable. Look for formulations specifically designed for oral use.
Protective pastes and films that coat the sore can also help. They shield the raw tissue from food, drinks, and friction, giving the area a better chance to heal without repeated irritation.
When You Need Prescription Treatment
For severe or recurring mouth sores, a doctor or dentist may prescribe what’s often called “magic mouthwash,” a custom-mixed rinse tailored to your specific situation. Depending on the cause, the prescription might include a numbing agent like lidocaine, a corticosteroid to reduce inflammation, an antifungal if yeast is involved, or an antibiotic for bacterial infections. Some formulations also include an antacid that coats the mouth for longer-lasting relief.
One important note if your mouthwash contains lidocaine: avoid hot drinks while your mouth is numb. The numbing effect extends to your throat, so you could burn yourself without realizing it.
Switch Your Toothpaste
If you get canker sores repeatedly, your toothpaste might be part of the problem. A systematic review of clinical trials found that switching to a toothpaste free of sodium lauryl sulfate (SLS), a common foaming agent, significantly reduced the number of ulcers, the duration of each episode, and the level of pain. The effect was consistent across all four measures of ulcer severity that researchers tracked. Most major toothpaste brands contain SLS, but SLS-free options are easy to find. Check the ingredients list on the back of the tube.
Nutritional Deficiencies to Address
Recurring canker sores are sometimes a sign your body is low on specific nutrients. The most commonly implicated deficiencies are iron, vitamin B12, folic acid, vitamin B3, and vitamin C. If your sores keep coming back, especially if they started appearing in adulthood, it’s worth getting blood work done to check these levels. Correcting the underlying deficiency can stop the cycle entirely. In one documented case, a patient with chronic recurring sores saw complete resolution after B12 supplementation.
You don’t need to wait for a test to start eating more leafy greens, lean meats, eggs, and citrus, all of which cover the key nutrients linked to mouth sore prevention. But if the problem is persistent, targeted supplementation based on actual lab results is more effective than guessing.
Signs a Mouth Sore Needs Medical Attention
Any mouth sore that lasts longer than two weeks is considered chronic and needs evaluation. At that point, the concern shifts from a routine canker sore to conditions that look similar but are more serious, including oral squamous cell carcinoma, which clinicians screen for whenever a single ulcer persists beyond that two-week window.
Other situations that warrant a visit: sores that are getting progressively worse over multiple episodes, sores accompanied by fever or other systemic symptoms, or a first onset of recurring sores after age 25. Large sores over 1 cm that are unusually deep or painful also fall outside the range of typical canker sores and benefit from professional assessment.