I have had to deal with trigeminal neuralgia for seventeen years. It is a savage, intolerable pain not touched by opioids. At first, my excellent doc tried Tegretol with ever diminishing results. We switched to a lab-made THC that is normally used for cancer patients.

Over night I went from 500mgs Tegretol with possible side effects that could affect my liver, to 2.5mgs of THC 24/7, which masks the pain 99.99%. It is legal, prescribed, and insurance pays. There are no side effects other than a trivial, rarely experienced, sense of being stoned, which does not affect my work, and quickly clears up. I carry a copy of the script with my driver's licence. Just in case.

Some docs are timid, and rigidly follow established protocols. The truth is that when they try to prohibit, they do not serve suffering people with empathy, on the face of it a bad idea.