The most prolific cannabinoid found in the living cannabis plant is not THC but rather its chemical precursor, Tetrahydrocannabolic Acid, or THCa. Unlike THC, THCa does not have psychoactive effects. However, structurally the only difference between THC's acid form (THCa) and its neutral form (THC) is a single molecule of Carbon dioxide (CO2). As shown in the graphic below, a process called "decarboxylation" removes that molecule of CO2, which results in converting THCa to THC. Decarboxylation occurs naturally in cannabis as it dries out, but it is also stimulated by exposure to light and/or heat.
NOTE: Categorized as a "Major" cannabinoid in cannabis.
Once the THCa is decarboxylated, the THC is now activated and can pass through our Blood-Brain-Barrier to provide its psychoactive effects.
NOTES: The Blood-Brain Barrier is semi-permeable; it keeps hormones and neurotransmitters that are not fat soluble from reaching the brain. A small amount of decarboxylation also occurs naturally during the drying and curing process of harvested cannabis.
Possible Therapeutic Effects
Just because THCa does not have psychoactive properties, doesn't mean it isn't medically valuable. Juicing of fresh, raw cannabis is a relatively recent trend that people are using in an attempt to take advantage of the potential health benefits of THCa.
-inflammation. Study 1.
-possible neuroprotective properties. Study 1.