Yes, it is possible to smoke parsley flakes, just as it is possible to smoke tea leaves or any other dried herb. What smoking parsley flakes will not do is to get anybody high when smoked. The worst, or best, depending on perspective, that could possibly happen is to get that light-headiness one sometimes gets when having a cigarette after not smoking for a while.
The reason parsley will not get a person high when being smoked is the fact that it has no THC in it. Quite a lot of youngsters seem to believe they can achieve a high if they just smoke enough of it. Even a kilogram of parsley could not produce the high of THC.
THC, or Tetrahydrocannabinol, is a psychoactive substance found in cannabis. Believed to be a kind of self defense mechanism against insects or herbivores, this aromatic terpenoid, which is a natural chemical, was first isolated in 1964. In its pure form, THC a glassy solid while cold, becoming sticky and viscous when heated.
The reason THC works the way it does on humans is that the human human body actually has two natural cannabinoid receptors. These receptors, CB1, which is located mostly in the human central nervous system, and CB2, which is present within the cells of the immune system, are partly activated by THC.
The psychoactive effect, the high that is experienced when smoking cannabis, is the result of the CB1 receptor being activated. THC also has some analgesic effects, meaning it acts like a painkiller. Many arthritis sufferers swear that using cannabis has changed their lives for the better.
Apparently studies have revealed that THC also has an action which may eventually lead to it being used in medication for Myasthenia Gravis and Alzheimer's.