THCa vs THC: Learn the Inside Secrets

THCa vs THC: Learn the Inside Secrets. Hand holding jar of high THCa Flower and examining THCa flower bud. Earthy Select

Comparing THC vs. THCa, can I learn the inside secrets? Most cannabis consumers know what THC is. But what about THCa? With two cannabinoids that sound and act so similar, it can be hard to demystify the differences between them. However, it’s essential to understand how THC and THCa differ in order to have the best cannabis experience possible. So, let’s dive right in. 

What is THCa?

THCa is short for tetrahydrocannabinolic acid. Though it’s a mouthful, the name simply signifies that the cannabinoid is the acidic form of Delta-9 THC.

The molecular precursor to Delta-9 THC (the psychoactive cannabinoid in cannabis plants), THCa is non-psychoactive yet contains its own potential benefits. Perhaps the most interesting bit of information about THCa for cannabis consumers may be what happens when its temperature elevates. Namely, THCa converts to Delta-9 THC when it is exposed to heat [1].

Thus, if you smoke, vape, or cook the plant, THCa converts to THC, making it psychoactive due to the structural change that occurs. Ta-da! All of a sudden, you have a product that has the potential to get you quite high yet while still retaining its federally compliant hemp status. That is, as long as it contains no more than 0.3 percent Delta-9 THC.

What is Delta-9 THC and Delta 8 THC? How do they relate to THCa?

We’ve established that THCa is the acidic precursor to Delta-9 THC, the main intoxicating compound in cannabis. In contrast, Delta-8 THC has the same number of atoms as Delta-9 THC, but their arrangements are different. This difference impacts their bond with endocannabinoid receptors, rendering THCa non-psychoactive and Delta-9 THC psychoactive.

Delta-8 THC is also derived from its own version of THCa, called Delta-8 tetrahydrocannabinolic acid, but there’s not a lot of research to show how Delta-8 and Delta-9 THC compare to each other in terms of their psychoactive effects. Nonetheless, both Delta-8 THC and Delta-9 THC have varying degrees of psychoactivity. Each form has progressed from its acidic form into psychoactive compounds in a process called decarboxylation [2].

Learn more in The Future of THC.

Does THCa get you high?

Nope. THCa is not a psychotropic cannabinoid. But that’s not the end of the story. Light it up, and you’ll have an ember packed with Delta-9 THC. So, if you do not want the psychoactive effects of Delta-8 or Delta-9 THC, it’s important to keep the THCa product or plant away from heat. Unlike THC, THCa does not have the molecular makeup to bond with the cannabinoid receptors that initiate psychoactivity. Therefore, if you eat freshly harvested cannabis, or make tinctures or extracts out of the raw plant, you can avoid turning it into a psychoactive substance.

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Is THCa illegal?

A lot of people are asking about the legality of THCa with good reason. The simple answer is no, it is not illegal under the federal Farm Bill (more on that below). Indeed, THCa is, in one respect, just another of the hundreds of non-psychoactive cannabinoids, at least in its raw form. Oddly enough, the DEA does not seem to give a hoot whether or not the cannabis in question first passed the USDA pre-harvest “total THC” test. So, at the end of the day, if your product contains less than 0.3 percent Delta-9 THC, it appears to be federally compliant. The DEA’s test is all about Delta-9 THC.

But here’s where the law gets a bit murky:

Though THCa is not a psychoactive cannabinoid, it can produce intoxicating effects after it is decarboxylated. The THCa content of a federally compliant hemp plant may, in fact, convert to the higher THC levels of its marijuana counterpart when its temperature is raised. Put another way, THCa becomes potentially as psychoactive as marijuana when it is smoked, vaped, or cooked, thus turning a federally compliant hemp product into something that could otherwise be considered a controlled substance. In this sense, THCa has a unique position under the law.

How could something just as psychoactive as marijuana be federally legal? The short answer is this: the USDA tests for “total THC” content only before cannabis is harvested, and then the DEA only tests for Delta-9 THC after it is harvested. So, when the DEA tests to ensure a plant is federally compliant, it will be considered hemp versus marijuana if the Delta-9 THC content is below the 0.3 percent threshold. The guidelines for assessing marijuana, on the other hand, test for “total THC” content, including THCa. This means that, conceivably, the same plant could be considered federally compliant hemp or as marijuana, depending on who’s testing it and for which market [3]. 

This difference in testing methods and guidelines gives sellers some leeway when marketing their products. For example, a product marketed as federally compliant hemp with high levels of THCa is not considered unlawful marijuana since its Delta-9 THC levels is below 0.3 percent Delta-9 THC.

But be careful. Even if your THCa product is federally compliant, it’s possible that law enforcement officials and/or legal representatives may misinterpret the law and erroneously label a THCa product with less than 0.3 percent Delta-9 as marijuana.

The fact is that THCa converts to Delta-9 THC when decarboxylated, yet retains the same legal status of its raw, unheated form post-harvest. This means that there is quite a bit of gray area between hemp and marijuana definitions when it comes to THCa.

The Farm Bills and the legality of cannabis

What initiated the explosion of the hemp market was the 2014 Farm Bill which removed hemp from the Drug Enforcement Agency’s list of Schedule 1 substances. The Bill made hemp, which was designated as cannabis with 0.3 percent or less Delta-9 THC, federally compliant and allowed long-forbidden research to begin after almost a century of prohibition.

Next, the 2018 Farm Bill allowed the production, sale, and consumption of hemp-derived products, making it clear to legal experts that all plant materials and substances derived from legally-defined hemp are federally compliant [4]. Of particular relevance to this article, hemp flower with high levels of THCa falls under this category, and is allowed by the 2018 Farm Bill.

Federal law now defines cannabis plants with less than 0.3 percent concentration of Delta-9 THC per dry weight as hemp plants and allows hemp production and consumption in all 50 states. The DEA does not test for other cannabinoids beside Delta-9 THC when determining its status after harvest.

Cannabis plants with more than 0.3 percent Delta-9 THC per dry weight, on the other hand, are defined as marijuana, which federal law still treats as a controlled substance on the DEA’s Schedule 1 list. But recently, some states have come to allow medical use and/or adult recreational use of cannabis containing much more than 0.3 percent Delta-9 THC.

THCa falls into a legal gray area. On the one hand, THCa is not psychoactive. On the other hand, it is derived from cannabis and will convert to THC when decarboxylated.

THCa versus THC

THCa has a similar chemical structure to THC yet has different functions when consumed. For example, because THCa has a carboxylic acid group and extra carboxyl ring compared to THC, the cannabinoid can’t bind to the brain’s receptors to produce psychoactive effects. But the chemical reaction that occurs when adding heat to raw cannabis changes the molecular structure of THCa to that of Delta-9 THC [1].

While THC is the most abundant cannabinoid in cannabis, THCa is the most abundant non-psychoactive cannabinoid in the cannabis plant. The most significant difference between these two chemical compounds is that THCa does not have psychoactive properties. THCa’s cannabinoid acid precludes it from bonding with the two major cannabinoid receptors in the same way as THC.

When it comes to other types of therapeutic potential, THCa and THC overlap in some areas. Both cannabis compounds have been associated with potential medicinal benefits but more research is needed to know if they can help with nausea relief, better sleep, chronic pain relief or other issues.

What is THCa powder?

Also referred to as THCa isolate, THCa powder is a pure extract of THCa made by removing the terpenes from the rosin, leaving behind only THCa. Next, the substance is further refined to produce THCa powder.

THCa powder contains a very high amount of cannabinoids but still is not an intoxicating cannabis product for the simple reason that it was not exposed to heat. Thus not decarboxylated.

Moreover, because the terpenes have been removed during the extraction process, they will not have the same smell or flavor as a hemp or marijuana plant [5]. 

What is THCa flower?

The cannabis industry is primarily concerned with the cannabis flower or bud, which is the most cannabinoid-rich part of the plant that is harvested for use. THCa hemp flower is marketed to people who intend to smoke or vape federally-compliant hemp.

Processed from freshly harvested cannabis, the THCa flower is generally sold unheated. Though the product may contain high levels of THCa, these federally compliant flowers contain only low levels of Delta-9 THC, rendering them lawful hemp as defined by the Farm Bills [4]. More specifically, the Delta-9 THC concentrations in THCa hemp flower must comprise less than 0.3 percent by dry weight. Yet, smoke or vape these flowers, and you will experience the psychoactive effects of Delta-9 THC.

What are THCa diamonds?

Cannabis forms THC diamonds (THCa crystalline) when the cured bud is refined from a gooey mixture referred to as cannabis sauce. This runny, sticky sauce is rich in THCa, other cannabinoids, and carboxylic acids [5].  

These gem-like nuggets are created by using multiple processes, usually beginning with the supersaturation of the cannabis biomass. Next, the mixture undergoes a chemical extraction process using hydrocarbons like butane or propane at low temperatures to help preserve the terpenes. The resulting live resins contain high concentrations of terpenes.

After the extraction process, the extract is put through a purging process to remove any residual solvents from the material. At this point, you need only wait several weeks for the diamonds to form into crystalline structures. Cannabis users enjoy using these high potency THCa diamonds for smoking or vaping [6].

How does THCa produce THC?

Put simply, THCa produces THC when it is heated. This could about come about by smoking, vaping, or cooking it. When applied to heat, the molecular structure of the cannabinoid is altered from its acid form as it loses its extra carboxyl ring in the decarboxylation process. At this point, it transforms into active THC. In its new incarnation, it can bind with the CB1 and CB2 receptors in the body’s endocannabinoid system and cause psychotropic effects.

Decarboxylation may take place with sunlight conversion or when THCa is applied to a direct heat source as with smoking or vaping. You can also cook your THCa cannabis if you want to use it in food, tinctures, or salves.

Cannabis strains with high THCa

In all states where recreational or medical cannabis is legal in the form of marijuana, cannabis retailers regularly test their products at third-party laboratories as part of the compliance and safety process. These tests determine both the THCa and THC content and advertise them as such.

Many of the products that are advertised as marijuana (for regulated marijuana markets) have high levels of THCa vs THC and are reported for their “total THC” content versus only their Delta-9 THC content. Unlike the testing process for hemp markets, all forms of THC are highlighted in their reports. The “total THC” reporting is acceptable to marijuana shoppers because many of them intend to smoke, vape, or cook the product, rituals that endow the cannabis with the most potent form of THC.

“Decarbing” your THCa hemp

THCa is activated, and converted to THC, when it is decarboxylated, or in practical terms, when it is heated.  After you’ve applied heat to your high-THCa hemp, you will end up with a batch of psychoactive cannabis because the THCa converts to THC in the heating process. If you want to decarboxylate (“decarb” for short) raw cannabis at home, place it in the oven at around 200-245ºF heat for half an hour. Don’t cook it too long or at higher temperatures, or you will burn away cannabinoids.

Health benefits of THCa versus THC

Though more research is needed for certainty, anecdotal reports indicate that THCa may help with a variety of maladies, possibly even nausea and insomnia. On the other hand, it’s clear that Delta-9 THC not only provides the euphoric effects sought by many but also has medical applications.

For example, the U.S. Food and Drug Administration (FDA) has approved THC-based medications such as dronabinol (Marinol®) and nabilone (Cesamet®). These pills can be prescribed by doctors to treat nausea in patients undergoing cancer chemotherapy or to stimulate appetite in patients with wasting syndrome due to diseases like AIDS [7].

More research must commence in order to confirm the health benefits of THCa, yet some preliminary findings are promising. For example, Dr. William Courtney, a California-based physician, told Fox News about the benefits of eating raw cannabis: “My experience day in and day out is overwhelmingly positive with patients who are using it.” Citing encouraging results with over 8000 patients, Courtney emphasizes that cannabinoids such as THCa possess outstanding therapeutic qualities. “It’s clear that this plant is incredibly important,” Courtney said [8].

How to consume THCa or THC

Most raw cannabis is rich in THCa if it has not been exposed to heat or has not undergone decarboxylation. Some people enjoy eating it raw, while others prefer juicing it to add to smoothies or other beverages.

Additionally, tinctures and topicals can be made with raw cannabis high in THCa. If you want to avoid getting high, make sure your cannabis is high in THCa rather than THC.

Risks and side effects

There are usually little to no adverse side effects from consuming THCa products, but if nausea or diarrhea occurs, stop taking it. The main risk may be the unwitting consumption of THC if the THCa has not been stored properly and has converted to Delta-9. Thus, if you’ve eaten a lot of what you thought was THCa, you may experience an intoxicating effect that you weren’t planning for. You want to know exactly what you are taking, so be sure to store your cannabis in a dry place away from any heat or direct sunlight so that its chemical makeup does not change. There could even be a room temperature conversion if the room is warm enough.

Final thoughts on THCa vs. THC

Whether you’re looking for unheated high-THCa cannabis for its potential benefits or want to turn it into Delta-9 THC for a more cosmic experience, there are myriad ways to enjoy cannabis products with this transforming cannabinoid. But make sure you understand what you’re consuming before smoking or vaping a product high in THCa. By just taking a puff, you’ll be turning your pipe into a tiny chemistry lab that will likely yield something extraordinary. Ready for the best? Check out Earthy Select’s small batch THCa Flower Strains

Learn more in the Guide to THCa

Medical Disclaimer / Legal Disclaimer – Information is provided for educational purposes. It does not and is not intended to constitute legal advice or medical advice. We attempt to be accurate and up-to-date, but the legality of cannabinoids and the science of cannabis are evolving. The author is neither a legal professional nor a medical expert. Before buying or using any products, you should check with your local authorities and medical providers.


  1. Tetrahydrocannabinolic Acid
  2. THCa vs. THC – What Are the Differences?
  3. THCa Flower – The Next Big Thing in Hempland?
  4. The HIA Position Statement on Delta-8 and Hemp Cannabinoids
  5. THC vs THCa Knowing the Differences
  6. Cannabis Diamonds and How They Are Made
  7. Is Marijuana Safe and Effective as Medicine?
  8. Is Juicing Raw Marijuana the Next Green Drink?
  9. Tetrahydrocannabinolic Acid is a Potent PPARγ Agonist with Neuroprotective Activity

Frequently Asked Questions

Yes, THCa is non-psychoactive and non-psychotropic. Yet, when it is heated, it is turned to Delta-9 THC, which is psychoactive and psychotropic.

The cannabinoids can degrade and lose their potency.

THCa isolate is concentrated pure THCa with high potency and purity.

COA stands for certificate of analysis. It’s simply a lab report detailing extensive breakdowns of what cannabinoids are in a product. For instance, consumers can check a COA to see what the THCa percentage is in a particular strain of THCa hemp flower.