General Advice

Mouth ulcers are really common and most people get one at some point in their life. Up to 25% of the population may get them repeatedly. [1] Recurrent mouth ulcers often first appear during childhood or when you are a teenager and in 80% of cases, they appear before you turn 30. [2] As you get older, you tend to get fewer of them and they’re usually less painful too. [2]

What are they?

Mouth ulcers are painful round or oval sores or sore spots that form in your mouth; often on the inside of the cheeks and lips. They can also appear on the floor of your mouth and on the underside of your tongue.

Mouth ulcers can be uncomfortable, especially when you eat, drink or brush your teeth, but they are not infectious and you cannot pass them from one person to another.

What are the main causes?

There are lots of things that can cause mouth ulcers, but they usually are due to you damaging your mouth, for example when you accidentally bite the inside of your cheek, brush your teeth too hard, or catch your cheek or lip on a sharp tooth or filling. They can also develop because you wear braces or dentures.

You can get mouth ulcers that keep coming back, mainly at times when you’re particularly stressed, anxious or ‘run down’. Some women can also develop them during their monthly period. [3]

Your diet can play part too and there are certain foods that may increase the likelihood of you getting a mouth ulcer. [15] These includes:

  1. Lemons
  2. Oranges
  3. Pineapples
  4. Apples
  5. Figs
  6. Tomatoes
  7. Strawberries

Stopping smoking may mean that you temporarily develop mouth ulcers, which is a normal reaction while your body is coping with chemical changes.

Sometimes, mouth ulcers keep coming back due to a lack of vitamin B12 or iron, a medical condition such as Coeliac or Crohn’s disease, or any condition where your immune system is suppressed, such as HIV or lupus. They can also be caused by a reaction to a medicinethat you are taking, including NSAIDs such as ibuprofen or aspirin, nicorandil (for angina), and beta-blockers (for conditions such as angina and high blood pressure). [3]

What are the symptoms?

A mouth ulcer is:

  1. Painful
  2. round or oval in shape
  3. usually red or yellow in colour
  4. swollen arount the edge

Most mouth ulcers appear on the:

  1. inside of the lips
  2. inside of the cheeks
  3. floor of the mouth
  4. under surface of the tongue

It's rare to get a mouth ulcer on the roof of your mouth.

What are my treatment options?

Most mouth ulcers don’t need any treatment and will heal on their own within a couple of weeks if they’re not interfering with your daily activities. If they’re painful, however, you can buy medicines without a prescription at your local pharmacy. Make sure you tell them who the medicine is for, as some aren’t suitable for under 16s. Ulcers don’t often lead to complications, but you could develop a secondary bacterial infection which can make them more painful and last longer. Treatments that help fight infection can therefore be useful.

What can I do about it?

The main goals for treating your mouth ulcer are to relieve your pain, reduce inflammation and help fight infection. There are two products in the bonjela range suitable for adults over the age of 16, designed to help you feel more comfortable and help fight infection; bonjela Adult and bonjela Cool Mint Gel. Designed to soothe pain, Bonjela Complete Plus is for adults over the age of 16. bonjela Junior Gel relieves pain and is suitable for adults and the elderly, as well as children over 5 months old.

bonjela Adult– sugar-free, clear, almost colourless, aniseed-flavoured gel for the relief of pain, discomfort and inflammation caused by common mouth ulcers and cold sores. It helps to fight minor mouth infection and aid healing of sore spots and ulcers due to dentures and braces.

(Medicine for adults over the age of 16) 

Always read the label.


bonjela Cool Mint Gel– sugar-free mint-flavoured gel for the relief of pain, discomfort and inflammation caused by common mouth ulcers and cold sores. It helps to fight minor mouth infection and aid healing of sore spots and ulcers due to dentures and braces.

(Medicine for adults over the age of 16)

Always read the label.


bonjela Complete Plus – for the treatment of 1 to 2 minor mouth ulcers ONLY (<1cm) as well as small wounds of the oral cavity. It is a gel which once applied in the mouth forms a fine and soft film which is intended to protect the wound from external things such as food, soothe pain and aid healing.

(Medical device for adults over the age of 16)

 Always read the label and instructions.


bonjela Junior Gel– sugar free, clear, almost colourless banana-flavoured gel for the relief of pain and discomfort from common mouth ulcers.

(Medicine for children over 5 months, adults and the elderly) 

Top Tips
  1. Clean your teeth properly and visit your dentist regularly.

  2. If you can tell what’s causing your mouth ulcer such as a sharp tooth or filling, visit your dentist so that they can repair it.

  3. Use a softer toothbrush when brushing your teeth and try switching to another toothpaste.

  4. Try to relieve your stress and anxiety by doing an activity that you find relaxing, such as meditating, practising yoga or other exercise.

  5. Eat a balanced diet with fresh fruit and vegetables, and avoid 'scratchy foods' such as toast, crisps and nuts.

  6. Don’t eat foods that you know can trigger your mouth ulcers.

  7. Talk to your GP about your medical condition or any medication that might be causing your mouth ulcers. You may be able to take a different medication.

Want to know more?

Find out more about bonjela

Find out more about bonjela Cool Mint Gel

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