To be orally active at the CB-1 receptors, the THC has to pass the blood brain barrier, which it can't readily in the polar THCA form. The CB-2 receptors are not protected by a blood brain barrier, so CBD ostensibly does not have to be decarboxylated.
We use coconut oil as a admix component, to tie up the liver, so as to leave the cannabinoids in our systems longer.