How much are silver nitrate sticks usually at the pharmacy? I'm having a REALLY painful canker sore on my lip?

Silve nitrate sticks do indeed stop a canker sore in its tracks. To get some, try calling a pharmacy and asking them. If your state lists them as a prescription drug, then ask a doctor or dentist - yes, dentist - for a prescription. They should give them to you. Another method you can try is simply eating blue cheese or Roquefort dressing on your salad. There seems to be something in blue cheese (other than the penicillin) that works quickly against canker sores. If you tend to have them frequently, ask your doctor if he can still get Smallpox vaccine, and ask him if he will vaccinate you 6 times, once every 2 weeks for 12 weeks, for a total of 6 vaccinations. The resulting very high titer of protection against Smallpox (Cowpox, actually) also seems to confer cross immunity to canker sores (). I used to get canker sores constantly when I was younger, but went through the Smallpox vaccinations back in the 60s, and never again had a canker sore, not even once in 40 years. It really works nicely! I'm just not sure if Smallpox vaccine is still available anymore. Talk to your doctor.