Core Cannabis Course: THCA

Welcome to homework assignment CCC 1.4 of the Core Cannabis Course from Higher Learning LV. This assignment teaches students about THCA, the acidic precursor to THC, the most common cannabinoid and also the most controversial based on its psychoactivity. Peer-reviewed scientific studies have shown that THCA may possess anticonvulsant, antiemetic (preventing or relieving nausea or vomiting), anti-inflammatory, and neuroprotective (nerve and brain cell preserving) properties.

When you complete this assignment, simply click the link at the bottom of the article to return to the master page for this course.

Tetrahydrocannabinolic acid (THCA) is the acidic precursor to the most infamous cannabinoid on earth, delta-9 tetrahydrocannabinol (THC). It is derived from the "mother of all cannabinoids," cannabigerolic acid (CBGA), which also produces the important cannabinoids cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA).

THCA molecular structure

Although not psychoactive, research has revealed that THCA delivers a wide range of potential medicinal benefits, including anti-inflammatory and anti-nausea properties. If decarboxylated with heat or a flame, THCA morphs into THC. This occurs when cannabis consumers vaporize or smoke the loose-leaf flowers of the plant.

THCA biosynthetic pathway

The primary potential medicinal benefits of THCA are found in its anti-inflammatory and anticonvulsant properties. However, it has also demonstrated neuroprotective and antiemetic properties.

THCA's antiemetic properties make this cannabinoid especially valuable to cancer and Crohn's patients undergoing chemotherapy. Neuroprotective efficacy means that dementia patients and those suffering Alzheimer's disease, Parkinson's disease, and Huntington's disease may benefit from THCA.

A 2022 study entitled "THCA → THC Conversion and its Importance for the Stability and Quality of the Herbal Material" that was published in the journal Macedonia Pharmaceutical Bulletin had the goal of providing "a deeper insight of the THCA → THC transformation and highlighting its importance in the stability and the quality of the herbal material by means of [a variety of leading edge analysis technologies].

The study reported that the pharmacology and biochemical characteristics of acidic cannabinoids such as THCA and their neutral analogs (such as THC) "has been found to be very different" and that an emerging segment of the cannabis research community is actively exploring the "pharmacology and medicinal use of acidic cannabinoids."

The scientists concluded that the THCA acidic precursor cannabinoid offers "potential pharmacological and medicinal use."

The research found that the conversion of THCA to THC via the chemical process of decarboxylation reached its maximum at a temperature of 266° F (130° C). Analysis confirmed complete conversion of the THCA contained in loose-leaf flower samples to THC at 320° F (160° C).

The scientists concluded that the THCA acidic precursor cannabinoid offers "potential pharmacological and medicinal use." They identified the maximum conversion temperature for the THCA contained in loose-leaf cannabis flower as 271° F (133° C).

View the original study.

A 2020 study entitled "Tetrahydrocannabinolic Acid A (THCA-A) Reduces Adiposity and Prevents Metabolic Disease Caused by Diet-induced Obesity" that was published in the journal Biochemical Pharmacology explored the potential positive efficacy of the cannabinoid THCA against obesity.

The study reported that cannabis has been employed "since the earliest written records of medical history" for a number of medical conditions. It noted that nearly 150 cannabinoids have been isolated from cannabis and that CBD and delta-9 THC are the most researched cannabinoids. The scientists noted that, in the plant itself, the neutral cannabinoids CBD and THC are stored as acidic precursors (CBDA and THCA).

The study found that, in a mouse model, administration of delta-9 THCA "significantly reduced fat mass and body weight gain."

The researchers reported that therapies involving THCA may be beneficial in the management of a number of metabolic disorders beyond obesity. Noted the scientists: "Obesity is a major risk factor for the development of multiple diseases, including prominently cardiovascular and metabolic disorders such as type-2 diabetes and metabolic syndrome (MetS). Given the conspicuous lack of effective therapies for the integral management of obesity, considerable attention is currently given to the identification of novel pharmacological agents," including cannabinoids such as THCA.

The study found that, in a mouse model, administration of delta-9 THCA "significantly reduced fat mass and body weight gain, markedly ameliorating glucose intolerance and insulin resistance, and largely prevented liver steatosis (fatty liver disease)." The study also identified potential anti-inflammatory benefits delivered by THCA. "Our data validate the potential of Δ9-THCA-A as capable of substantially improving the symptoms of obesity-associated metabolic syndrome and inflammation."

View the original study.

A 2020 study entitled "Influence of Temperature and Heating Time on the Decarboxylation of Δ9-THCA and CBDA in the Cannabis Inflorescences" (flowers) that was published in the UPB Scientific Bulletin investigated "the influence of temperature and heating time on the decarboxylation of Δ9-THCA and CBDA."

The study reported that cannabinoids are manufactured, or biosynthesized, via enzymatic processes that occur in "specialized gland cells of the plant called trichomes" that are available mostly in the flowers of the mature female plants (although they sometimes appear on sugar leaves, fan leaves, and even the stem of the plant). "The most abundant cannabinoids are Δ9-tetrahydrocannabinol (Δ9-THC), which is the main psychoactive cannabinoid and cannabidiol (CBD), which is one of the most important pharmacologically active cannabinoids," noted the scientists.

"The study's authors concluded that around 302° F (150° C) is the optimal decarboxylation temperature and 10 minutes the optimal time for converting maximum THCA into THC."

The research found that the decarboxylation process by which THCA converts to THCA increases as the temperature increases. It found that the conversion rate of THCA to THC varied only marginally at different temperatures, which it noted indicates "a complete conversion of Δ9-THCA into Δ9-THC. The study noted that this dynamic was not the case for CBDA, where different temperatures resulted in secondary compounds in addition to CBD.

The study's authors concluded that around 302° F is the optimal decarboxylation temperature and 10 minutes the optimal time for converting maximum delta-9 THCA lacking psychoactivity into the neutral and psychotropic THC. The study also revealed that significant portions of the THC that was decarboxylated from THCA further morphed into CBN.

View the original study.

Juicing the leaves of mature cannabis plants is one of the best ways to get THCA into your body. However, many patients and consumers do not have access to the raw leaves of the plant. Such consumers can create infused food with loose-leaf flower that they purposefully do not decarboxylate.

Some companies sell products like tinctures that provide THCA suspended in alcohol or oil that can be absorbed sublingually or eaten.