Cannabis grows and produces THCa and CBDa. THCa and CBDa are precursors to THC and CBD. Both have very similar properties to THC and CBD. When cannabis is heated, through smoking, cooking, or vaporization, a process known as decarboxylation occurs. Decarboxylation is whats responsible for converting the THCa and CBDa into THC and CBD. Unlike THCa, where it becomes psychoactive after decarboxylizing into THC, both CBDa and CBD are non-psychoactive.