<<Disclaimer: Verify this information before applying it to your situation.>> I received 5 replies re novocaine. As with a lot of things there seems to be no pattern. I would still welcome responses. Nancy in nyc 1. Sometimes there is a nerve that runs near the back teeth that can make it very sensitive. ... I needed 3 doses of novocain, that wore off quickly, and I still had pain (but somewhat tolerable) when she drilled. Much depends on the layout of your mouth. Mileage will vary. 2. Have trouble with numbing .I just had 2 root canals: first was never completely numb.When told I needed another on the next tooth I cried. Went to a diferent endodonist and he gave me mepergan(I believe the brand Weyth) and ingections of citinest,some into the tooth. The topical gel I do not think is GF.I called about the mepergan,it is GF. 3. Mother has CD and Novicane does not work on her. For a recent tooth extraction Doctor gave her the maximum amount and it still did not work. He finally had to give her laughing gas. 4. I dont know if connected to Celiac but i am extremely allergic to all local anesthesia. You are right..it does not kill pain when you have this problem!!! It took me finally going into anaphalectic shock and also my heart stopped after surgery one time. Its no fun and your choice but not worht trying again as allergies only get worse. A few years ago the anest dept at MCV canceled some mouth surgery because they said that it is very rare for a person to be allergic to caines and usually was additives involved. They said can give it to you straight and when i refused, the medical school said they had a skin test for it now and in 8 years no one had a positive reaction. So with a little uneasiness i agreed to go to allergy dept to be tested. I WAS the first person they tested that had a positive reaction and it didnt take but three sticks. Now it is documented. Have your dr write a note documenting what happened to you because no one had done that for me before this test. 5. Novocaine always killed my pain for dental work but causes swelling afterward; I think this is pretty standard.