Get medical help if a canker sore persists for more than two weeks, is larger than one cm (about the size of a pea), or is accompanied by a fever or difficulty eating and drinking.
Self-care guide
Canker Sores
For minor canker sores, a small number of trials suggest short-term symptom relief from specific oral preparations of chamomile, aloe, myrrh, or Psidium guajava. Evidence is limited and product-specific; these options do not replace evaluation of persistent or unusual ulcers.
Step 1 · First-line care
What to do first
For a typical minor canker sore, use gentle oral care, avoid irritating foods and products, and try only one clearly labeled oral preparation at a time. Do not use skin products, essential oils, or homemade extracts in the mouth; stop if irritation or allergy occurs.
Step 2 · Safety
When to get medical help
Get medical help if consult a doctor if they are accompanied by other symptoms such as joint pain, diarrhea, or unexplained weight loss.
Extra caution: Children with poor intake or dehydration, immunocompromised people, people receiving cancer therapy, and people with persistent or atypical oral lesions need earlier clinical evaluation. Canker sores should not be confused with cold sores on the lip, traumatic ulcers, dental infection, or persistent lesions requiring cancer assessment.
Step 3 · Optional ingredient support
For relief now
These options have been reviewed for evidence and key safety concerns.
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Matricaria Chamomilla Topical
Short-term symptom relief for minor recurrent aphthous ulcers; evidence is specific to chamomile tincture mouthwash, not all topical chamomile products.
How it is used: Use only a commercially prepared oral chamomile mouthwash labeled for mouth use and follow its directions; do not swallow. Stop if irritation or allergy develops.
What does this evidence mean?
One randomized trial in oral aphthae reported improved clinical outcomes with chamomile tincture mouthwash versus control. Applicability is limited to the studied mouthwash preparation, short-term use, and minor aphthous ulcers; evidence is not transferable to creams, essential oil, or ingestion.
Evidence may apply to one specific form of an ingredient — a capsule, extract, cream, or tea — and to a particular amount. Recipes and everyday foods may not match the form or amount that was studied.
Aloe Vera Topical Gel
Possible short-term relief for minor mouth ulcers using an oral aloe gel preparation.
How it is used: Use only a product specifically labeled for oral use and follow its label; do not substitute skin gel or ingest large amounts.
What does this evidence mean?
A controlled trial reported benefit from aloe vera gel for common mouth ulcers. The evidence is limited by the available secondary report and does not establish that every aloe product, concentration, or non-oral gel works; it is symptom treatment, not prevention.
Evidence may apply to one specific form of an ingredient — a capsule, extract, cream, or tea — and to a particular amount. Recipes and everyday foods may not match the form or amount that was studied.
Commiphora Myrrh Topical Gel
Possible short-term relief for minor mouth ulcers using the studied myrrh gel preparation.
How it is used: Use only a commercially prepared oral myrrh gel labeled for mouth use and follow its directions; do not swallow. Stop if irritation occurs.
What does this evidence mean?
A controlled trial reported benefit from myrrh gel for common mouth ulcers. Evidence is limited by the available secondary report and is specific to the studied topical oral preparation; it should not be generalized to myrrh oil, tincture, or ingestion.
Evidence may apply to one specific form of an ingredient — a capsule, extract, cream, or tea — and to a particular amount. Recipes and everyday foods may not match the form or amount that was studied.
Psidium Guajava Herbal Gel
Possible short-term symptom relief for recurrent aphthous ulcers using the studied Psidium guajava herbal gel.
How it is used: Use only the studied or a comparable commercially prepared oral gel, if available, and follow its label; do not improvise a homemade preparation or swallow it.
What does this evidence mean?
A randomized study reported clinical benefit for a Psidium guajava-based herbal gel in recurrent aphthous stomatitis. Applicability is limited to that formulation and studied population; it does not establish benefit for guava tea, leaves, food, or other gels, nor prevention of recurrence.
Evidence may apply to one specific form of an ingredient — a capsule, extract, cream, or tea — and to a particular amount. Recipes and everyday foods may not match the form or amount that was studied.
For ongoing support
These options are better suited to regular or longer-term use than to quick symptom relief.
No reviewed options in this category yet.