What is THCa Flower?

What is THCa flower? Earthy Select. A woman smells high THCa hemp flower. Cannabis in background.

In recent years, there has been a surge in the use of cannabis for wellness and recreational purposes. Cannabis plants naturally contain compounds known as cannabinoids, which are prized for their various mood-altering effects. One such compound is THCa or tetrahydrocannabinolic acid, found in abundance in the raw, unprocessed form of cannabis plants.

This unique cannabinoid has found its way to more and more dispensary shelves as cannabis becomes more accessible. Here we’ll delve into THCa flower’s unique attributes and explore how it differs from other cannabis products.

A non-intoxicating compound, THCa converts to THC

Does THCa get you high? It’s complicated. THCa is the acidic precursor to THC (tetrahydrocannabinol), the primary psychoactive compound in cannabis plants. When cannabis plants are harvested and dried, the THCa in the plant slowly decarboxylates – a process that converts it into THC. When a user smokes, vapes, or cooks the cannabinoid, it converts quickly to its psychoactive counterpart. However, if the plant is not dried or heated, the THCa remains acidic, which precludes the psychoactive effects [1].

THCa flower contains high levels of THCa. People typically consume it through smoking or vaporizing, but other consumers also enjoy it orally in tinctures. Some even blend it into foods like morning smoothies [1]. THCa flower is increasingly popular as more people seek the benefits of cannabis without the psychoactive effects associated with THC.

Benefits of THCa flower

One of the main benefits of THCa flower seems to be its potential wellness effects, yet more research is needed to explore this compound’s efficacy in this area [2]. Studies have found that THCa may have potent qualities but more research is needed to conclude THCa’s ability to treat any condition [3].

Learn more in the Guide to THCa.

What’s the difference between THCa flower and CBD flower?

Since both cannabinoids come from cannabis, are they the same? Related, but no. THCa flower is grown to have high levels of THCa. CBD flower is grown to have high levels of CBD and low levels of THC. These differences allow people to use the type of cannabis they need and avoid certain aspects they don’t want.

Since both cannabinoids exist in natural cannabis, there will be some amount of each in any typical cannabis plant, and in a full-spectrum product. Full-spectrum indicates that the full plant is included. For instance, full-spectrum CBD oil is derived from the hemp plant and contains high concentrations of CBD (cannabidiol) and lower concentrations of THC [5].

Challenges associated with THCa flowers

One of the challenges of THCa flower is also its super power! THCa is prone to a process called decarboxylation, which is the chemical transformation of THCa into THC via heat and light.

Though some people seek out THCa flower products for their ability to convert to high levels of THC, others desire the non-psychoactive, wellness effects. Therefore, it is crucial to store THCa flower in dark, cool places after harvest if you want it to retain its acidic chemistry.

Is THCa flower legal?

It’s important to note that the legal status of hemp and THCa flower is subject to change as laws and regulations around cannabis evolve in each state. As more research occurs regarding the potential health benefits of THCa and other cannabis compounds, individual states may redefine their guidelines around hemp and marijuana products.

While THCa flower is federally compliant for recreational use (as long as it is derived from federally compliant hemp), it may be restricted in certain states. Yet, according to the language of the 2018 Farm Bill, any compound derived from hemp (that contains no more than 0.3 percent Delta-9 THC per dry weight) is federally compliant. Even if the total THC content exceeds 0.3 percent, federal law does not concern itself with THCa content post-harvest [7]. Thus, many more people now have the freedom to enjoy the benefits of high THCa raw hemp flower.

THCa flower is federally compliant if:

  • The product is derived from federally compliant hemp, and
  • It has 0.3 percent Delta-9 THC or less, on a dry weight basis.

Though the language of the 2018 Farm Bill allows for hemp with high THCa concentrations, individuals need to  understand their state’s laws around THCa flower.

Read: THC Flower: Is it Legal in My State?

How is THCa flower different from marijuana?

The main difference between THCa flower and marijuana is the THC level. Surprisingly, it doesn’t matter if THCa hemp flower products can convert into higher THC levels. Indeed, if the tested amount of Delta-9 THC in a cannabis flower product is below 0.3 percent, the DEA considers it hemp, not marijuana. [7]

Nonetheless, some cannabis with high THCa levels may be able to produce the same effects as marijuana if exposed to  heat and thus decarboxylated. And by the same token, be aware that THCa can show up on a drug test.

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THCa and the Controlled Substances Act

In 1970, the Controlled Substances Act (CSA) labeled cannabis a Schedule I drug, imposing severe legal penalties for its cultivation or use. Banning all “tetrahydrocannabinoids,” the CSA failed to differentiate between marijuana and hemp, criminalizing any cannabis, including non-psychoactive compounds [8]. Thanks to the 2014 and 2018 Farm Bills, products such as CBD flower, smokable hemp flower, and high-THCa flower are now widely available.

The 2018 Farm Bill and THCa flower

The 2018 Farm Bill cemented the initial progress made by the legalization of hemp research in the 2014 bill. Yet, with the new bill’s passage, the federal government removed the “industrial hemp” ban, differentiating hemp from “marijuana.” By doing so, the government removed hemp from the list of Schedule I substances [9]. In contrast, marijuana is still considered federally illegal and defined as having more than 0.3% Delta-9 THC.

The DEA’s 2020 Interim Final Rule (IFR)

The DEA regularly enacts policies as interim final rules (IFR). As such, in response to legal questions regarding the legality of hemp substances such as THCa, the DEA issued an IFR to clarify its stance. In the IFR, the DEA states that the only criteria for cannabis derivatives qualifying as a lawful hemp product under the 2018 Farm Bill is that hemp products must contain less than 0.3 percent Delta 9 THC. So if a hemp product like THCa contains less than 0.3% THC at the time of sale, the DEA letter seems to indicate that it is hemp, not marijuana [10].

The Alabama Board of Pharmacy letter

For some, the above-referenced IFR didn’t wholly quell questions regarding the legality of hemp products. Noting the rise of cannabis products in their state, the Alabama Board of Pharmacy wrote a letter to the DEA in 2021. They soon received a response from the DEA clarifying that cannabinoids extracted from hemp (that contain less than 0.3 percent Delta-9 THC) meet the federal definition of hemp [11].)

The DEA cannabis seed letter

Early in 2022, the DEA confirmed, once again, that substances “extracted from the cannabis plant” with a “Delta-9-tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis meets the definition of ‘hemp’ and thus are not controlled under the CSA.” Though the letter addressed a question about cannabis seeds, it also applies to THCa [12].

The bottom line: is it legal to smoke or vape THCa?

Since smoking or vaping can easily convert THCa to THC, it might be confusing. In the natural course of these consumption methods, THCa can become as psychoactive as marijuana. So, why aren’t the two cannabinoids regulated in the same way?

Some cannabis theorists propose that the illegality of THC may be hanging on by a thread. Others say it now seems that the federal government may not want to deal with the hassle of cannabis reform as much as the nation wants to legalize it [10].

Cannabis enthusiasts are glad that many producers are no longer apprehensive about growing high-THCa hemp. Now it’s possible to buy THCa flower whether you want to use it for wellness or recreational purposes or to get high. The Farm Bill made hemp products lawful under federal law, but consumers should stay aware of their state’s rules when considering THCa.

Up next: How to Use THCa for Great Results

Medical Disclaimer / Legal Disclaimer – Information is provided for educational purposes. It does not and is not intended to constitute legal 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. What is THCa?
  2. THCa and Inflammation Study
  3. THCa Potent Agonist with Neuroprotective Activity
  4. THCa as Anti-emetic in Rat Models 
  5. Difference Between THCa, THC, and CBD
  6. Benefits of CBD
  7. THCa-The Next Big Thing in Hempland
  8. THCa and the Controlled Substances Act 
  9. THCa and the 2018 Farm Bill
  10. Is THCa Flower Legal?
  11. The Alabama Board of Pharmacy
  12. The DEA Seed Letter-Triumph or Trap?
  13. What is THCa?-The Parent of THC

Frequently Asked Questions

The answer is yes. Many drug tests look for THCa as a target analyte [13].

Since THCa is part of the natural growth process of cannabis (whether hemp or marijuana), hemp will contain some amount of THCa during its life cycle. THCa hemp flower strains are specifically grown to contain high concentrations of THCa.

THCa hemp flower with less than 0.3% Delta-9 THC by dry weight is federally compliant and lawful under the Farm Bill. Smoking regulations vary by state and municipality. For instance, even states that sanction medical or recreational marijuana use may not allow smoking it in public places, etc.  Please be aware of state and local rules before purchasing THCa products.