An ulcer appears in the mouth that is oval with a gray center and surrounding red, inflamed halo. The ulcer last for one to two weeks.


What is a Canker Sore?

From Modern Western Medicine

A small, painful sore or ulcer that appears in the mouth, on the inside of the cheek or lip or underneath the tongue. The ulcer, which usually disappears without treatment, may arise from hemolytic streptococcus bacteria, an organism that frequently appears with canker sores. Other possible causes include trauma to tissues (such as from a toothbrush or dental injection), acute stress, and allergies. They are common in women during the premenstrual period. Topical ointments may relieve the pain.


From Traditional Medicine

Sores arise as a discharge of waste that is not being cleansed by the liver and kidneys. Canker sores, therefore, indicate a depressed liver and kidney function. Treatment consists of strengthening both of these organs so that blood can be more efficiently cleansed and detoxified.

Who Gets Canker Sores?

Minor canker sores affect about 20% of the population at any given time. They are most common between the ages of 10 and 40 and affect women more than men. The most severely affected people have continuously reoccurring ulcers; others just have one or two ulcers per year.



See Part IV for methods of strengthening liver and kidneys, especially of canker sores appear chronically.

Foods to Eat

Eat foods that are easy to digest:

  • Do a one- to three-day carrot-juice fast
  • Wheatgrass juice or liquid chlorophyll: drink 2 oz., three times a day
  • Soft grains, well cooked
  • Lightly cooked vegetables


Foods to Avoid

  • Dairy products
  • Oily foods
  • Sweets such as cakes, candies, and raw fruit
  • Salty foods
  • Animal protein
  • Less liquid


Herbs to Treat Canker Sores

  • Bayberry tincture: 15 – 30 drops as needed. Fluid extract: ½ – 1 tsp. as needed. Decoction: simmer 10 – 15 minutes; 1 tbsp.
  • Burdock: a great blood cleanser that clears the kidneys of excess waste. Tincture: 30 – 60 drops, three or four times per day. Fluid extract: ½ – 1 tsp., three to four times per day. Decoction: 1 oz. root to 1½ pints of water, boiled down to 1 pint; 3 oz., three to four times per day. Infusion: 1 cup, three to four times per day
  • Goldenseal tincture: 20 – 90 drops, three times per day. Fluid extract: ¼ – ½ tsp., three times per day. Decoction: simmer 15 – 30 minutes; 1 – 2 tsp., three to six times per day
  • Lobelia tincture: apply several times a day



  • Goldenseal and myrrh: make an herb tea and gargle four to five times per day
  • Rosemary, thyme, or juniper berry oils: 3 drops to 1 cup of warm water, gargle
  • Wheatgrass juice or liquid chlorophyll: gargle
  • Black tea: at first inkling of a sore, apply a wet black tea bag to the ulcer; the tannin is an astringent with pain-relieving ability