Tetrahydrocannabinolic Acid (THCA)
The most common cannabinoid found in the raw cannabis plant. THCA is non-intoxicating but converts into the intoxicating THC when exposed to heat through a process called decarboxylation. Research indicates that THCA has its own medicinal potential in anti-inflammatory, neuroprotective, and anti-emetic treatments.
“What’s the difference between THC and THCA?”
“You won’t get high from eating a raw cannabis plant because the THCA has not yet converted to THC.”
More About THCA
You’re probably already familiar with tetrahydrocannabinol (THC), the most common cannabinoid in the cannabis plant. You may have also noticed THCA products becoming more prominent in the cannabis market in recent years. So what is THCA, what is the exact nature of its relationship to THC, and what is its place among other well-known cannabinoids?
THCA is produced in trichomes, the tiny glandular hairs found across the surface of the cannabis plant. Trichomes are responsible for producing the cannabis plant’s cannabinoids and terpenes. Trichomes contain resin glands that make the terpenes, THCA, and other phytocannabinoids.
Cannabinoids are produced in trichomes through biosynthesis, a process in which enzymes trigger a series of chemical reactions to make complex molecules out of smaller, simpler ones. The enzymes responsible for creating the cannabinoids with which most of us are familiar are cannabidiolic acid (CBDA) synthase, cannabichromenic acid (CBCA) synthase, and tetrahydrocannabinolic acid (THCA) synthase. THCA synthase takes the central cannabinoid precursor CBGA and converts it into THCA, in addition to several other acidic cannabinoids.
THCA converts into THC through decarboxylation, the process of heating a cannabinoid to the point of removing a carboxyl group. Decarboxylation enhances this cannabinoid’s ability to interact with the body’s cannabinoid receptors.
What’s On the Label?
At this point, you may be wondering how your dispensary-purchased cannabis flower is tested for THC potency if the THCA has not yet been decarboxylated. The THC amount you see on a label is actually a measurement of total potential decarboxylated THCA.
What’s the Difference Between THC and THCA?
The cannabis plant produces hundreds of cannabinoids, but only a few of them cause the euphoric high that is unique to the cannabis plant. Most people assume that the cannabis plant produces THC during the growth period, when it is actually primarily producing a larger molecule: THCA.
THCA is the non-intoxicating precursor that becomes THC when exposed to heat over a prolonged period of time. THCA from a raw cannabis plant won’t make you feel high. This is why you can eat or drink the raw plant and not feel its intoxicating effects.
But what keeps THCA from producing the intoxicating effects of THC? Simply put, the THCA molecule doesn’t fit into the brain’s cannabinoid receptors. THCA’s three (3)-dimensional shape is different than THC, due to an extra carboxyl group attached to the molecule. This carboxyl group is what makes THCA an acid. In fact, most cannabinoids (CBDA, CBGA, THCVA) take this acidic form when harvested, and it is only later that they become the cannabinoids we’re more familiar with (CBD, CBG, THCV).
The medicinal value of THCA has gone somewhat overlooked in favor of cannabinoids such as THC and CBD. However, studies have shown that THCA has anti-inflammatory, immunoregulatory, anti-tumor, neuroprotective, and antiemetic properties.
THCA exhibits anti-inflammatory effects by inhibiting cyclooxygenase enzymes (COX-1, COX-2), and modulates immune-activity through metabolic pathways other than CB1 and CB2. It can also act as a potent neuroprotectant by activating Peroxisome proliferator-activated receptor-γ (PPAR-γ) pathways, and may inhibit prostate cancer growth along with other non-THC cannabinoids.
Mechanism of Action
Without decarboxylation, THCA has very little affinity for the cannabinoid type 1 (CB1) receptor, and is therefore incapable of producing intoxication. Decarboxylation changes the three (3)-dimensional shape of THCA, and this new shape (THC) favors the binding pocket of the CB1 receptor. CB1 receptors are largely found in the central nervous system, where they regulate a wide variety of brain functions, and facilitate the intoxicating and pain-relieving effects of THC.
THCA is a highly unstable compound, which makes it difficult to observe or protect a sample from THC contamination. We have been able to observe, however, that THCA interacts with several receptor pathways other than CB1 and CB2, including COX-1 and COX-2 enzymes, tumor necrosis factor alpha (TNF-alpha) proteins, and the cytokine interleukin 10 (IL-10).
Raw Cannabis Flower
You may have recently stumbled upon raw cannabis as an interesting ingredient in the search for a super-healthful juice or smoothie recipe. And no, it’s not a mistake, nor is it another baseless food fad. Raw cannabis has massive potential as a superfood alongside avocados and kale. More consumers are looking for smoothie and juice recipes to consume raw cannabis for the non-intoxicating, medicinal benefits of THCA.
Tea and Topicals
Other popular non-activated, non-decarboxylated products include tea and topicals. Cannabis tea is typically not heated at high enough temperatures for THCA to decarboxylate into THC, making it a mildly-to-non-intoxicating substance that will appeal to those who drink tea for immunoregulatory and general medicinal purposes.
Topicals are cannabis-infused products applied directly to the skin for medicinal purposes, allowing for cannabinoids to be absorbed into the bloodstream at a slower rate than if cannabis were smoked or eaten. Similarly to cannabis tea, topicals can be a great choice for people who want relief without the full intoxicating side effects. Topicals that include THC may prove mildly intoxicating, but only if THC reaches the bloodstream. And even then, this happens so slowly that most people don’t detect any intoxication or psychoactivity. Topicals infused with THCA are non-intoxicating.