Canker Sore Treatment

Canker Sore Numbing Agents


Those shallow ulcerations you can get in your mouth, technically called aphthous stomatitis but more commonly known as canker sores, can cause quite a bit of discomfort. They can be caused by stress, a minor mouth abrasion or a host of other reasons. While they will heal in a week or so, most people will do almost anything to relieve the sting.

If you have one of these ulcers, you have probably tried a number of remedies. If you are looking for something to get rid of the pain, there are a variety of numbing products  that will do the trick.  Here is the good and the bad on various numbing agents you can find at the drugstore:

Over-The-Counter Numbing Gels and Ointments

Orajel offers several formulas. The Film-Forming Canker Sore Gel contains 15% Benzocaine plus 2% Menthol. You apply it with a cotton swab or your finger and it dries in about 60 seconds and forms a protective film. This product also contains Alcohol (76.4% by volume) and there is a warning on the package that says the product is flammable, and that you shouldn’t smoke during application and until the product has dried. Yikes!

A second product, Orajel Ultra Mouth Sore Medicine, contains Benzalkonium Choride Solution 0.02%, which is an oral antiseptic to help prevent infection, 20% Benzocaine to numb the pain and 0.1% Zinc Chloride, which is an astringent to help dry out the ulcer. Both products do a decent job at relieving the pain.

Anbesol Pain Relief, Instant, Maximum Strength, Liquid with 20% Benzocaine is a liquid. The problem is, it is runny so it is easy to either swallow some of it by accident, get it in other areas of your mouth besides your ulcer, thereby numbing a bigger area of your mouth, and it may not stay very long on your sore due to saliva washing it away. As with other numbing products, it ironically causes a stinging sensation when first applied, but then the numbing kicks in and relief comes. Probably the best way to use this product (though far from ideal) is to coat a cotton ball with the stuff and then tuck the ball in your mouth against the sore and try to keep it there as long as you can. Of course this will not work so well if your mouth ulcer is on your tongue or on the roof of your mouth.


Zilactin-B – A thick medicated gel containing  10% Benzocaine to provide pain relief by numbing the ulcer. This gel forms a film over the mouth sore and it lasts up to six hours. Essentially it seals in the medication and helps prevent bacteria from getting into the ulcer. It can be used up to four times per day. It goes on a dark purple so you can see where you are putting it so you don’t end up numbing your whole mouth. Some people say it stings when first applied. It appears to be quite effective for mouth sores on the tongue, which is a particularly difficult area to treat effectively.

Kanka Mouth Pain Liquid, Professional Strength .33 oz (9 ml) is a mouth pain liquid that also forms a protective coating inside the mouth. In addition to being a numbing agent, it acts as a barrier against irritation. It contains 20% Benzocaine, which is the maximum allowed without a prescription. It can be used up to four times per day, according to the package directions. It also stings upon applications and some people say it hurts quite a bit at first.  It is a bit more messy than Zilactin and tends to spread more easily to other non-affected parts of the mouth, numbing them as well.

Benzocaine Cautions

A word of caution about benzocaine in the products mentioned above. While it can provide temporary pain relief, do not use this in young childRen. In fact all products carry a warning about not using the product on any child under the age of two. According to medicinenet.com the FDA issued a warning in April 2011 about benzocaine and a rare but serious condition called Methemoglobinemia, whereby oxygen delivery to body tissues has been adversely affected. Furthermore, if you are allergic to local anesthetics such as procaine, benzocaine or any other “caine” you should not use this product. You should not use any of these products for more than seven days – and hopefully your sore should have healed by then anyway. If not, consider seeing a medical professional if it has not healed in two weeks.

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