Cannabidiol acid (CBDA) occurs in the resin glands (trichomes) of the cannabis plant. It is the precursor of cannabidiol (CBD).
CBDA is considered inactive until it is activated and then becomes active CBD. To activate CBDA, it must be outdated and go through a heating process (decarboxylation) to convert it to CBD.
Heat causes the acid molecules of CBDA to break down and become activated CBD. CBDA is found in cannabis strains with a high CBD content.