Originally Posted by mrsD

Prolotherapy is not recommended much anymore because it turned out it was not so "harmless". The toxin I think in your injection was not the lidocaine, but the other you list.
People get --caine anesthetics every day in joints. I've had 4.
all with no bad long term effects.

Some people have IV lidocaine for allodynia or severe RSD or chronic systemic pain conditions. Lidocaine is a sodium channel blocker, and does not linger in the body for long.

Many drugs cross the blood brain barrier...this depends on their lipophilic characteristics. Also as we age, this barrier deteriorates and may do so if essential fats are deficient in our diets.