A gel containing the Aloe vera polysaccharide acemannan was found in one double-blind trial to speed the healing of canker sores better than the conventional treatment Orabase Plain.¹ The gel was applied four times daily. Because acemannan levels can vary widely in commercial aloe gel products, it is difficult to translate these results to the use of aloe gel for canker sores.

Licorice that has had the glycyrrhizic acid removed is called deglycyrrhizinated licorice (DGL). Glycyrrhizic acid is the portion of licorice root that can increase blood pressure and cause water retention in some people. The wound-healing and soothing components of the root remain in DGL.

A mixture of DGL and warm water applied to the inside of the mouth may shorten the healing time for canker sores, according to a double-blind trial.² This DGL mixture is made by combining 200 mg of powdered DGL and 200 ml of warm water. It can then be swished in the mouth for two to three minutes, then spit out. This procedure may be repeated each morning and evening for one week. Chewable DGL tablets may be an acceptable substitute.

According to preliminary reports, some people with recurrent canker sores may respond to topical and/or oral use of Lactobacillus acidophilus³ and Lactobacillus bulgaricus.⁴ However, a double-blind study found no effect of acidophilus bacteria on the healing time of canker sores.⁵

Several preliminary studies,^6,7,8,9 though not all,¹⁰ have found a surprisingly high incidence of iron and B vitamin deficiency among people with recurrent canker sores. Treating these deficiencies has been reported in preliminary^11,12 and controlled¹³ studies to reduce or eliminate recurrences in most cases. Supplementing daily with B vitamins—300 mg vitamin B1, 20 mg vitamin B2, and 150 mg vitamin B6—has been reported to provide some people with relief.¹⁴ Thiamine (B1) deficiency specifically has been linked to an increased risk of canker sores.¹⁵ The right supplemental level of iron requires diagnosis of an iron deficiency by a healthcare professional using lab tests.

Zinc deficiency has also been linked with recurrent canker sores in preliminary studies¹⁶ and in one case report.¹⁷ A preliminary trial found that supplementation with up to 150 mg of zinc per day reduced recurrences of canker sores by 50 to 100%; participants who were zinc deficient experienced the most consistent benefit.¹⁸ However, a double-blind trial (that did not test people for zinc deficiency) did not find zinc supplements helpful for recurrent canker sores.¹⁹

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.

Because of its soothing effect on mucous membranes (including the lining of the mouth) and its healing properties, chamomile may be tried for canker sores and other mouth irritations.²⁰ A strong tea made from chamomile tincture can be swished in the mouth before swallowing, three to four times per day. Goldenseal has also been used historically as a mouthwash to help heal canker sores.

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.

The antiviral, immune-enhancing, and wound-healing properties of echinacea may make this herb a reasonable choice for canker sores. Liquid echinacea in the amount of 4 ml can be swished in the mouth for two to three minutes, then swallowed. This procedure may be repeated three times per day. However, no research has investigated the possible effects of this treatment.

Because of its soothing effect on mucous membranes (including the lining of the mouth) and its healing properties, chamomile may be tried for canker sores and other mouth irritations.²¹ A strong tea made from chamomile tincture can be swished in the mouth before swallowing, three to four times per day. Goldenseal has also been used historically as a mouthwash to help heal canker sores.

Myrrh, another traditional remedy with wound-healing properties, has a long history of use for mouth and gum irritations. Some herbalists suggest mixing 200 to 300 mg of herbal extract or 4 ml of myrrh tincture with warm water and swishing it in the mouth before swallowing; this can be done two to three times per day.

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.

Several preliminary studies,^22,23,24,25 though not all,²⁶ have found a surprisingly high incidence of iron and B vitamin deficiency among people with recurrent canker sores. Treating these deficiencies has been reported in preliminary and controlled studies to reduce or eliminate recurrences in most cases.^27,28,29 In addition, a double-blind study found that supplementing with vitamin B12 prevented recurrences even in people who were not deficient in the vitamin.³⁰ The amount used in that study was 1,000 mcg twice a day for six months. Supplementing daily with B vitamins—300 mg vitamin B1, 20 mg vitamin B2, and 150 mg vitamin B6—has been reported to provide some people with relief.³¹ Thiamine (B1) deficiency specifically has been linked to an increased risk of canker sores.³² The right supplemental level of iron requires diagnosis of an iron deficiency by a healthcare professional using lab tests.

Historically, herbs known as astringents have been used to soothe the pain of canker sores. These herbs usually contain tannins that can bind up fluids and possibly relieve inflammation. They are used as a mouth rinse and then are spit out. None of these herbs has been studied in modern times. Examples of astringent herbs include agrimony, cranesbill, tormentil, oak, periwinkle, and witch hazel. Witch hazel is approved by the German Commission E for local inflammations of the mouth, presumably a condition that includes canker sores.