THCA, or tetrahydrocannabinolic acid, is the non-psychoactive acid form of THC that is found in the marijuana plant when the plant is still raw. In layman's terms, this means that the marijuana plant itself cannot get you high. In order to derive THC from the plant – the part that does get you high – the plant needs to be heated. Aside from smoking or vaporizing the plant, THC can also be gleaned from THCA by baking the marijuana into edibles (which is why pot brownies get you high) or by heating the plant in a process known as decarboxylation.
It is estimated that over 95 percent of THCA is converted to THC during the heating process. This means that a marijuana smoker might actually inhale the remaining five percent, which may provide the smoker with a therapeutic feeling. Some doctors believe that THCA may be effective at treating epilepsy, and that it may also be used as an anti-inflammatory medicine, or a drug used to reduce nausea. What is particularly interesting about THCA is that it is able to produce a result at a very low dose. Doctors do not need to use a lot of it to see its effect.
By contract, CBD – another element of cannabis that can only be released artificially – must be used in greater quantities before results are observed. For instance, Epidiolex, a pure CBD spray, must be used at a dosage that is 10-100 times greater than the dosage of THCA that is used to produce a similar result. THCA is usually administered as an under-the-tongue dropper or as a spray. Interestingly, the higher the dosage of THCA, the worse a patient may do. As it is, higher doses of THCA do not tend to produce more improved results.
At this point, however, research into THCA has provided more confusing than helpful results due to their inconsistency. While lower doses of THCA have been shown to reduce nausea in rats, it is also believed that THC and THCA are distributed throughout the body differently. This is why different patients on similar dosages of THCA, or who smoke similar amounts of marijuana, may experience different results. In this way, THC and THCA resemble alcohol in that it doesn't so much depend on the dosage, but more on the body type of the person consuming it.
The only receptor that THCA has been confirmed to bind to strongly is TRPM8. This is the same receptor in one's brain that makes minty things feel cold. There is no research to suggest that inhibiting the TRPM8 receptor prevents a person's nausea or reduces his or her seizures, so this does not explain the effects that have been observed when THCA is introduced into the body. Conversely, in higher dosages, THCA may actually activate the TRPV4 receptor, which helps us sense heat, like that which we may feel after eating spicy mustard or cinnamon. In a nutshell, we still have so much more to learn in this field.