Novacane directly acts on the nerves in a radius on where it's injected. It does not have any psychological effects, it's all physiological... as far as I know. It has been done to me several times. Just know that your jaw and shit will be completely numb for like 3 hours. Sometimes they give you nitrous oxide, too. I'm not sure how it would feel to be on nitrous and pot at the same time. Nitrous makes me feel nervous... that's all I know.