What is the difference between THC and THCA?

Tetrahydrocannabinolic Acid or THCA is a raw, unheated compound in freshly-harvested cannabis plants. Like other cannabinoids in the C. Sativa, THCA works in the body to relieve pain, inflammation, and also for treating symptoms of conditions such as seizures and arthritis. THCA has been closely compared to THC. However, while tetrahydrocannabinol or THC is the main psychoactive ingredient found in the Sativa plant, THCA is non-psychoactive and will not cause a “high” feeling. 

What is tetrahydrocannabinolic acid and what does it do?

Tetrahydrocannabinolic acid synthase is the enzyme responsible for the production of THC and is often referred to as its precursor. Both THCA and THC have similar chemical compositions but THCA has one other carboxyl group. THCA is a cannabinoid acid that is converted to its non-acidic form, THC through a process known as decarboxylation, a chemical reaction that uses heat or light that removes one group of carboxylic acids, altering the THC chemical structure.

The CB1 and CB2 receptors in the endocannabinoid system (ECS) play a role in regulating functions in the body like mood, sleep, memory, and pain. The “high” effect of THC is because it binds to the CB1 receptors mostly found in the brain and central nervous system. However, unlike THC, THCA doesn’t bind effectively with these receptors. This is because of the three-dimensional shape of the THCA molecule. It is also larger and can’t fit into the CB1 receptor. This means that THCA will not get you high.

Does THCA have good health benefits? 

There is limited research on THCA and its effects but preliminary research suggest that THCA has anti-inflammatory properties, neuroprotective properties, anti-emetic properties, anti-proliferative properties, and can be an effective treatment for conditions such as:

• Treatment of Lupus and Arthritis. A study was published by the Biological and Pharmaceutical Bulletin wherein they found that THC along with six other major cannabinoids from the C. Sativa has anti-inflammatory properties that can help treat conditions like lupus and arthritis.

• Relief from Nausea. A study was published by the British Journal of Pharmacology and found that THCA appears to be an anti-emetic and can be a therapeutic treatment for nausea and vomiting. It was also mentioned that it may be a more effective treatment as it does not cause psychoactive effects.

• Treatment of Cancer. A study was published by the Journal of Pancreatic Cancer found that cannabinoids derived from THCA have anticancer effects and may decrease pancreatic tumour cells without producing unwanted psychotropic effects.

THC vs THCA

THCA has been closely compared to THC because they have similar chemical compositions, but they provide different effects and benefits. THC binds with the CB1 receptor resulting in a euphoric effect. Since THCA does not bind well to the same receptor, its therapeutic potential is different, mostly because it binds with the CB2 receptors responsible for regulating immune signalling and inflammatory responses in the body. THCA has also been found to protect the leaves of C. Sativa plants from harmful UV-B light radiation.

In what part of the cannabis plant can you find THCA?

THCA is found in the trichome resin glands on the surface of the leaves and flowers of C. Sativa plants. One research suggested that THCA produces necrosis in cannabis leaves. When the Sativa plant secretes chemicals into its leaves, it causes cells to die. This means that THCA can be an external immune system that allows the plant to prune itself and recycle the nutrients to other parts of the plant.

Does THCA's relationship with THC make it Illegal in the UK?

Under the Misuse Drugs Act of 1971, it is illegal to grow, possess, and distribute cannabis in the UK as most cannabis products contain more than 0.3% THC, causing a high effect on consumers. There are no clear specifications about other cannabinoids so we can assume that THCA is also not legal in the UK. Currently, the only cannabinoid legal in the country is Cannabidiol or CBD as they only contain the legal amount of THC which is less than 0.3%. 

The Takeaway

THCA is one of the cannabinoids found in cannabis plants that is being studied for its potential health benefits. Though it is an unprocessed form of THC, it won’t give you a “high” effect the way that THC can as it doesn't interact with the same cannabinoid receptors. Some of the known benefits of THCA include reducing inflammation and fighting nausea as it interacts with the receptor responsible for regulating functions in the body.

However, there is still limited research on the compound THCA and its full potential. Understanding the plant’s properties and how they interact with our cannabinoid receptors is important to achieve its full effects and avoid adverse side effects.  If you are studying THC you can find more useful reference material online PubMed Europe PMC Abstract as well as supplementary material.