Mouth ulcer treatment: home care and when to worry

Health advice ·Published 24 September 2026 ·Reviewed 7 October 2026

Written by the Priceline Pharmacy Pacific Fair team. Reviewed by Jason Markey, BPharmSci, MPharm, Owner and Pharmacist.

General health information from a registered pharmacist. It doesn’t replace advice from your own pharmacist or doctor.

Most mouth ulcers heal on their own within 1–2 weeks, so mouth ulcer treatment is mainly about easing the pain while you wait. Saltwater rinses, soft foods, a soft toothbrush and a numbing gel or protective product from the pharmacy can all help. The key rule is simple: if an ulcer hasn’t healed after 2 weeks, or they keep coming back, see your dentist or GP. You’ll find more conditions like this in our common illnesses A–Z.

What is a mouth ulcer?

A mouth ulcer is a sore that forms on the soft lining inside your mouth: the inside of your cheeks or lips, on or under your tongue, or on your gums. The most common kind are aphthous ulcers, also called canker sores. They aren’t contagious, and they’re different from cold sores, which usually appear on the outside of the lips and are caused by a virus.

Mouth ulcers are very common. The Better Health Channel says around 20 per cent of the population experiences aphthous ulcers, and healthdirect notes they often run in families.

Quick check: does this sound like a mouth ulcer?

• A shallow, round or oval sore with a white or grey centre and a red rim.
• Usually small; healthdirect says they’re typically smaller than 5mm.
• Stings or hurts when you eat, drink, talk or brush your teeth.
• Extra painful with spicy, salty or acidic food.
• Redness or slight swelling around the sore.
• You might have one ulcer or a small cluster.

A sore that is painless, or one that looks different from this, still needs attention. The Better Health Channel notes that some ulcers, including those linked to mouth cancer, don’t hurt.

What causes mouth ulcers?

Often there’s no single clear cause, but common triggers include:

• Minor injuries: biting your cheek, a slip of the toothbrush, a sharp tooth, braces, aligners or dentures that rub, or burning your mouth on hot food.
• Stress, anxiety or feeling run down.
• Hormonal changes, such as around your period.
• Certain foods, which for some people include chocolate, peanuts and coffee.
• Low iron or B-group vitamin levels.
• Some medicines or medical treatments.
• Viral infections.
• Health conditions such as coeliac disease or Crohn’s disease.

Mouth ulcer treatment at home: a checklist

These self-care steps are based on advice from healthdirect and the Better Health Channel.

• Rinse with warm salt water a few times a day. Dissolve about a teaspoon of salt in a glass of warm water, swish gently and spit it out.
• Switch to a soft toothbrush and brush gently around the sore, but keep brushing. Good oral hygiene helps.
• Choose soft, bland foods while it heals, and skip anything hot, spicy, salty, crunchy or acidic. On a Gold Coast beach day, that might mean giving the salty hot chips and the lime in your drink a miss for a few days.
• Use a straw for drinks if it’s very painful.
• Stay hydrated. Keep a water bottle handy, especially in the heat.
• Try not to touch or poke the ulcer with your tongue or fingers.
• Notice your triggers. If ulcers keep appearing after a certain food or a stressful week, that’s useful information for your pharmacist, dentist or GP.

How can a pharmacist help?

Your pharmacist can take a look, check it’s likely to be a simple ulcer, and help you choose something to make eating and talking more comfortable. Pharmacy options include:

• numbing (anaesthetic) mouth gels that may ease pain for a while, which is handy before meals;
• protective gels and pastes that form a barrier over the ulcer;
• antiseptic mouthwashes;
• anti-inflammatory mouth products. Some stronger options need a pharmacist’s advice or a prescription;
• pain relief such as paracetamol or ibuprofen, if they’re suitable for you.

Some products aren’t suitable for young children, or during pregnancy or breastfeeding, so ask your pharmacist which suits you and follow the label or your pharmacist’s advice.

If a medicine you take might be causing ulcers, or you keep getting them, it’s worth mentioning. A medication review can help you look at your medicines as a whole.

When to see a dentist or GP

healthdirect and the Better Health Channel both say to see a doctor or dentist if an ulcer lasts longer than 2 weeks, or if ulcers keep coming back. The Australian Dental Association lists an ulcer that’s present for longer than 2 weeks, or keeps returning, among the possible signs of mouth cancer. Most won’t be cancer, but it’s important to get it checked, especially if you smoke or drink alcohol regularly.

Also see your GP or dentist if you have:

• a painless ulcer, a lump, or a white or red patch in your mouth;
• very large ulcers, lots of ulcers at once, or ulcers that are getting bigger;
• so much pain that you can’t eat or drink enough, especially in young children;
• a fever of 38°C or more;
• unexplained weight loss, tummy pain or blood in your poo;
• ulcers in other places, such as around the anus, or new skin rashes;
• ongoing difficulty swallowing, or swollen glands in your neck that don’t settle.

If mouth pain or swelling makes it hard to breathe or swallow, call 000.

If you need a doctor, the Help Medical GPs inside our store are close by. Your dentist can also check your mouth, and regular dental check-ups include a look for oral cancer.

This article is general information only and isn’t a substitute for personal advice from your doctor or pharmacist. Always read the label and follow the directions for use. If symptoms persist or you’re worried, talk to your pharmacist or GP. In an emergency, call 000.