The knowledge and experience I have with cannabis is the following: Raw dope, sorry cannabis, contains, among a myriad of ingredients and properties (many still unknown due to being a Schedule I drug with no known medicinal value) something known as THCa, a substance devoid of psycho-active effects. This is the precursor to THC. In order to be transmuted through a process known as “decarboxylation” into THC (which does have psycho-active effects) heat must be applied to the THCa.
Ergo, people who wish to indulge in the aforementioned psycho-active effects will make narrow cylinders encased in thin paper around the dried “leaves” of this plant and apply a flame to one end while inhaling from the other end, in much the same way as tobacco is applied to the human organism.
This heat is what will cause the THCa to be transmuted into THC.
One can also cook with cannabis to decarb the THCa, providing that the temperature does not exceed 300 degrees F, when the THC will begin to burn itself away. Many folks suggest lower temps and longer cooking times for maximum THC extraction as well as for keeping the active terpenes, another constituent of this plant. Over 100 different terpenes have been identified in the cannabis plant, and every strain tends toward a unique terpene type and composition. With their unlimited combinations of synergistic effects, it’s likely that terpenes will open up new scientific and medical areas.
My own experience was, hearing that raw cannabis had positive health effects, grinding up raw buds into a powder that I kept on the dining-room table which for a time I would add to salads etc., like one adds salt. It produced no psycho-active effects at all.
My other anecdote involves one of my goats who had managed to stick her neck through the garden fence and chew off and eat some flowering buds. I was worried about her, but after maybe a day or two of just sitting there, I imagine she had gotten high in some way, she finally got up and continued her goatly existence. But then again, a goats digestion (4 stomachs) is quite different to that of a human being.