Delta THC | Science

THC VS THCa Compared: Benefits, Risks and Effects

Dr Abraham Benavides


Dr Abraham Benavides

Medical Doctor

Many cannabis users are familiar with Delta 9 THC. It’s the famous cannabinoid that gives you the quintessential intoxicating “high.”

There are actually around 150 recognized cannabinoids found in cannabis. THC just happens to be the most commonly known, found, and understood.

THCa is a lesser-known cannabinoid often found in freshly harvested cannabis. 

Even though THC and THCa have the same prefix, there are striking differences between the two cannabinoids.

What is THCa? How do these two chemical compounds compare?

Read on to learn about how THC and THCa differ. And why it’s significant. 

thc trichomes

What is THCa?

THCa is short for tetrahydrocannabinolic acid. It’s one of the major cannabinoid acids produced by cannabis and hemp plants.

THCa is a non-intoxicating compound. It doesn’t successfully bind to CB1 and CB2 receptors in the brain. 

In order for us to feel psychotropic effects, it would need to activate the CB1 receptors in the brain. So THCa doesn’t get you high.

On the other hand, THC, or tetrahydrocannabinol, is an active derivative of THCa. THC binds with CB1 and CB2 receptors in our endocannabinoid system (ECS), so it does get you high. Binding CB2 promotes anti-inflammatory and immune system effects. 

THCa Is The Precursor To THC 

Here’s where THCa and THC are closely related.

Cannabinoid acids turn into the main cannabinoids across time as a matter of nature. 

THCa is commonly described as the precursor to THC. This is because THCa actually transforms into THC.

People often believe that cannabis plants produce THC. However, the freshly harvested cannabis plant is high in THCa. There is very little THC present in fresh raw cannabis.

It only becomes present when THCa is converted into THC. 

So how does this occur?

bud flower

THCa Converts Into THC

THCa turns into THC via a process called decarboxylation.

During this process, a chemical reaction occurs where a carboxyl group is removed from THCa. This alters the chemical structure where THCa converts to THC.

What causes decarboxylation to take place?

The THCa in raw cannabis transforms into THC with exposure to:

  • Sunlight
    • UV exposure will eventually turn THCa into THC
  • Heat
    • Sufficient heat exposure such as: smoking, vaping, cooking, baking, and extended exposure to room temperature activates THCa, turning it into THC.
  • Aging
    • Over time, compounds naturally break down by themselves

THCa is not very stable, and It easily converts to THC. 

Related Read: THCa VS Delta 9

Benefits of THC VS THCa Compared 

THCa has some similar benefits to THC.

However, THCa is not psychotropic. It does not produce intoxicating effects.

This is because its chemical structure, or shape, doesn’t fit into the CB1 receptors. THC does. Since THCa is a weak agonist, it doesn’t cause any mind-altering effects.

The science on THCa remains limited. But some recent research suggests that medicinally, THCa has potential benefits.

These are some of the potential benefits of THCa: 

cannabis bud

Anti-inflammatory properties

A 2017 study suggested that THCa had more anti-inflammatory properties than CBD. The research showed the anti-inflammatory activity of cannabis on colon cells was derived from Delta 9 THCa extract. 

Researchers suggested that raw cannabis containing THCa may be a more precise treatment for patients with IBD.

Even though it may ineffectively bind to CB2, THCa may bind to the GPR55 receptor at least partially to exert its anti-inflammatory effects.


In a study conducted on mice, THCa can also bind and trigger PPARγ (a group of receptors that regulate glucose metabolism and fatty acid storage) with greater potency than other decarboxylated cannabinoids.

It is typical for cannabinoids and cannabinoid acids to bind to many receptors with different binding strengths.

Since THCa displayed strong neuroprotective properties, researchers suggested that it be considered for treating neuroinflammatory and neurodegenerative diseases.

Weight Management

A 2019 study found that THCa can support weight management. It was shown to reduce fat mass, weight gain, and fatty liver disease in mice.  


Research on anticonvulsant effects of THCa had mixed results in preclinical tests. When combined, certain mixtures of THC and THCa were anticonvulsant in a 6-HZ threshold test but increased the severity of spontaneous seizures in mice. 

When they were dispensed individually, they were proconvulsant in a different threshold test. Cannabinoids are known to have different effects depending on their concentrations and the presence of other compounds, so further study is needed.


A 2013 study examined the anti-nausea properties of THCa in animal models. 

Researchers found that it reduced vomiting in rats. Concluding that THCa may be a more effective alternative to THC in treating nausea and vomiting. 

Due to the potential benefits of THCa without psychoactive effects, it is commonly used for therapeutic purposes.  

thc concentrates

THC compared to THCa Products 

The legality of THC vs THCa products varies.

Delta 9 THC is a Schedule I substance. This means it is federally illegal. The government considers Schedule I substances, including cannabis, to be highly addicting and possess no medical use.

The Food and Drug Administration (FDA) doesn’t categorize THCa as a federally outlawed substance.

Due to the current loopholes of the 2018 Farm Bill, Delta 9 isomers and edibles are legal.

Delta 9 products are available nationwide as they contain <0.3% Delta 9 THC based on a dry weight basis.

High THC products do not adhere to the 2018 Farm Bill restrictions. So outside of medicinal or recreational states, these products aren’t legally available.

To determine whether flower products are categorized as THCa or THC, it is tested for potency. Flower products must be third-party tested via liquid chromatography or gas chromatography using pre-established standards. 

Liquid chromatography or gas chromatography testing works by separating a sample to identify its individual parts.

With this testing, the THC and THCa potency can be analyzed. 

What THCa products are available today?

In some states, these types of THCa are available:

THCa Flower

This is a new upcoming trend in the Hemp industry.

THCa flower is hemp flower rich in THCa. While It must have <0.3% Delta 9 THC content, it can contain as much THCa as it likes and still be classed as Industrial Hemp. 

In short, THCa flower is available in regular raw hemp flower that can be selectively bred to be naturally high in THCa.

8% THCA Flower | Secret Nature
  • Indoor grown hemp flower
  • 8% THC-A
  • Top shelf buds

Hemp flower is often harvested early to prevent tetrahydrocannabinolic acid from turning into Delta-9-THC.

However, some freshly harvested cannabis strains are naturally rich in THCa.

Strains rich in THCa are usually milder, with 7-8% THCa and 5-7% CBD. Similar to the old-school potency of the 1960s.

Nonetheless, this is a risky endeavor. As noted earlier, THCa is unstable and only needs the smallest amount of energy to turn into THC via decarboxylation. 

THCa Isolate in legal cannabis markets

This isolate is available in legal cannabis markets.

THCa isolate is a highly pure and potent concentrate. All of the impurities from THCa are removed, leaving it in its pure powder-like form. However, it does not carry any beneficial terpenes or other naturally occurring compounds found in whole plants.

While it is unregulated at the federal level, if it turns into active THC it immediately becomes a Schedule I substance. 

Wrapping Up THC-A and THC 

Though THCa and THC sound similar, they have significant differences.

To cannabis consumers, THC remains the most well-known of both cannabinoids. But its precursor is essential in its own right.

THCa research is still very new. But some studies have shown that THCa has a multitude of medicinal benefits minus the intoxicating effects.

It may be beneficial for those seeking therapeutic effects, similar to THC, without mind-altering effects.

Though the FDA doesn’t ban THCa, it can quickly become illegal via heating, smoking, aging, or exposure to UV light. In some states, it can also be considered an analog of THC, rendering possession of the substance a crime.

Keep a lookout for THCa. We predict that these products will be making major waves in the cannabis industry shortly.