Canker Sores

Canker sores are ulcers that appear inside the mouth. They're not contagious. Their exact cause is unclear, but they have been linked to local trauma, stress, hormone changes, micronutrient deficiencies, and viral infections. They often heal on their own, but gels and mouthwashes can be used to alleviate symptoms.

Quick Answer

What it is

Canker sores are ulcers that appear inside the mouth. They're not contagious.

Key findings

  • Grade B: Canker Sores Symptoms (Aloe Vera)

Safety

No specific caution or interaction language was detected in the current summary/outcome notes.

ℹ️ Quick Facts

Quick Facts: Canker Sores

  • Supplements Studied:4
  • Research Trials:5
  • Total Participants:5,657
  • Top Supplement:Aloe Vera (B)
5 trials
5,657 ppts
4 supps · 4 outcomes

Evidence-Based Protocol

Supplement stack ranked by research quality

Moderate Evidence

Primary Stack (Tier 1)

1000mcg sublingual daily (methylcobalamin)

Deficiency associated with recurrent aphthous ulcers; supplementation reduces recurrence

8 studies | 500 participants
1000-1500mg daily; increase to 3000mg during outbreaks

May inhibit viral replication and support tissue healing

6 studies | 300 participants

Supporting Stack (Tier 2)

Only if deficient: 30-60mg elemental iron daily

Iron deficiency is a common cause of recurrent canker sores; correct if deficient

8 studies | 600 participants
400-800mcg daily

Deficiency linked to aphthous ulcers; supports mucosal health

6 studies | 400 participants
25-50mg daily during outbreaks; 15mg maintenance

Supports immune function and wound healing; may reduce ulcer duration

6 studies | 300 participants
2000-4000 IU daily

Supports immune regulation and mucosal immunity; deficiency linked to recurrent ulcers

5 studies | 300 participants
10-20 billion CFU daily (Lactobacillus strains)

Support oral and gut microbiome; may reduce inflammation and recurrence

5 studies | 200 participants
1-2g EPA+DHA daily

Anti-inflammatory effects may reduce frequency and severity of ulcers

4 studies | 150 participants

How It Works

Canker sores (aphthous ulcers) are painful, shallow ulcers that appear inside the mouth - on the cheeks, lips, tongue, or gums. Unlike cold sores, they're not caused by herpes virus and aren't contagious. Minor canker sores (most common) heal in 1-2 weeks; major ones can take 6 weeks. They can be triggered by mouth injury, stress, acidic foods, certain toothpastes (sodium lauryl sulfate), hormonal changes, and nutritional deficiencies. Some people get them repeatedly (recurrent aphthous stomatitis).

CRITICAL: Occasional canker sores don't require medical attention, but see a doctor if ulcers are unusually large, extremely painful, don't heal in 3 weeks, spread, accompanied by fever, or occur very frequently. Recurrent canker sores may indicate underlying conditions: celiac disease (screen if frequent), inflammatory bowel disease, Behçet's disease, or nutritional deficiencies. Rule out these conditions before assuming the cause is unknown. OTC treatments (Orajel, Kank-A) provide symptomatic relief.

* Vitamin B12 has the strongest evidence for recurrent canker sores. A clinical trial showed 1000mcg sublingual B12 significantly reduced outbreaks even in patients without measurable deficiency. The mechanism may involve nerve and tissue health.

* Lysine is an amino acid that some find helpful, though evidence is limited. It may support tissue healing.

* Iron, Folic Acid, and Zinc deficiencies are all associated with recurrent aphthous ulcers. Get tested - correcting deficiencies often dramatically reduces recurrence.

* Vitamin D deficiency has been linked to recurrent canker sores in several studies.

* Probiotics support the oral and gut microbiome, which may modulate the inflammatory response that causes ulcers.

* Omega-3 Fatty Acids have anti-inflammatory effects that may help reduce ulcer frequency and severity.

Expected timeline: Topical treatments relieve pain immediately. For prevention, supplements typically require 1-3 months to assess benefit. B12 study showed significant improvement within 5-6 months.

Generated from peer-reviewed researchSchema v2.0

Supplements for Canker Sores

Sorted by strength of evidence

Detailed Outcomes

|
B
Canker Sores Symptoms
Small improvement in canker sore healing
2 studies
small↓Improves
?
Canker Sores Symptoms
1 study
↓Improves
?
Canker Sores Symptoms
1 study
↓Improves
?
Canker Sores Symptoms
1 study
↓Improves

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