THCA and THC: What's the difference?

Contrary to what some slapstick comedies would have you believe, eating raw weed is not going to get you high. No matter how much potential resides within raw, freshly harvested cannabis, there is practically none of the plant's most famous and intoxicating cannabinoid, delta-9-tetrahydrocannabinol (THC). There is, however, a wealth of tetrahydrocannabinolic acid (THCA), an inactive compound found in the trichomes of living cannabis plants.

THCA has been closely compared to THC, but these days most describe THCA as the precursor to THC. While it's easy to get the two confused, it's important to know they produce very different effects when consumed. 

If you're looking to understand why we get high on THC and not THCA, how cannabinoid acids convert into cannabinoids, and why some consider raw cannabis a superfood, welcome. We've got a lot to unpack. 

marijuana plant
As a marijuana plant grows, it is ramping up THCA levels.
Photo by: Gina Coleman/Weedmaps

Why does THC get us elevated and THCA doesn't?

The reason is due to the shape of the THCA molecule. It is a larger molecule that doesn't fit into certain cannabinoid receptors, specifically the CB1 receptors. You can find CB1 receptors primarily in the brain, central nervous system, lungs, liver, and kidneys. In order to have an intoxicating effect, a cannabinoid must fit into a CB1 receptor. 

The cannabis plant produces hundreds of cannabinoids, the chemical compounds responsible for the potential therapeutic and psychoactive effects of cannabis. Only a few cannabinoids contribute to the euphoric high that is unique to the cannabis plant, though. The most celebrated, researched, and sought-after is THC.

It's commonly assumed that as a marijuana plant grows, it is ramping up THC levels until ripe for the picking. But the primary cannabinoid being produced is actually THCA. So, how does THCA become THC?

How THCA becomes THC

The simplified answer is through heat and light — or the process of decarboxylation. Heat removes a carboxylic acid group from THCA, altering the THC chemical structure. This makes it the perfect shape to fit into our endocannabinoid system (ECS) and the CB1 receptors that run throughout our central nervous systems, allowing for that classic elevated experience.

Though THCA doesn't have intoxicating effects, some consider fresh, raw, unheated cannabis a superfood. You may have heard of juicing cannabis or adding raw cannabis to smoothies for health enhancement. There's a good reason for that.

Much like avocados, kale, Greek yogurt, green tea, and garlic, raw cannabis has the potential to ease arthritis, chronic pain, fibromyalgia, and other ailments.

THCA is believed to offer an assortment of medicinal benefits and is commonly used as a nutritional supplement and dietary enhancement for the following properties:

Anti-inflammatory. A 2011 study published in the Biological and Pharmaceutical Bulletin suggested that, along with other cannabinoids, THCA demonstrated anti-inflammatory properties in lab studies. In a 2021 study using mice, THCA shows great potential as a treatment for fatty liver disease because of its anti-inflammatory traits. 

Neuroprotective. Research, including a study conducted on mice published in 2017 in the British Journal of Pharmacology, points to THCA's ability to help protect against neurodegenerative diseases.  

Anti-emetic. This is the quality of increasing appetite and decreasing nausea. A 2020 study published in the journal Psychopharmacology found that both THCA and CBDA were effective in reducing nausea and vomiting in rat models, even more so than THC and CBD.
Anti-obesity. A 2020 study that looked at mice and was published in the journal Biochemical Pharmacology demonstrated THCA's apparent ability to reduce obesity and associated diseases including diabetes and fatty liver disease. As with all of the above findings, more research is needed before drawing any definitive conclusions.

cannabis and joint container
If a cannabis plant sits in the warm sun for an extended period of time, its THCA molecules will slowly convert to THC.
Photo by: Gina Coleman/Weedmaps

THCA isn't the only cannabinoid acid

Most cannabinoids, including cannabidiol (CBD), cannabigerol (CBG), and tetrahydrocannabivarin (THCV), are in the acidic form (CBDA, CBGA, and THCVA) when cannabis is harvested. The unactivated forms of THC and CBD — along with other cannabinoids — have potential benefits that are still being discovered. Just like THCA, these cannabinoid acids are unactivated until they go through the decarboxylation process and become capable of interacting with the human ECS.

THCA vs. THC: decarboxylation process

Even though the most common decarboxylation process involves toasting cannabis in the oven to convert THCA into THC, there are many ways that weed can be decarboxylated, or decarbed.

Sunlight conversion. THCA converts to THC in varying degrees through exposure to heat or light. If a cannabis plant sits in the warm sun for an extended period of time, its THCA molecules will slowly convert to THC. 

Room-temperature conversion. THCA also converts to THC when stored at room temperature for a long enough time. When submerged in olive oil, 22% of THCA will convert over the course of 10 days at 77 degrees Fahrenheit (25 degrees Celsius). Under the same conditions, 67% will convert when submerged in ethanol. Over time, cannabis stored at room temperature with a little light exposure will convert 20% of its THCA into THC. Bottom line: THCA is unstable and can convert to THC over time with little intervention. 

Smoking. When a flame is used to smoke dried, cured bud, the high degree of heat applied in a short amount of time rapidly converts THCA to THC. However, not all THCA will convert and even though smoking is the most common way to enjoy THC's effects, it's not the most efficient.

smoking a bubbler
When a flame is used to smoke dried, cured bud, the high degree of heat applied in a short amount of time rapidly converts THCA to THC.
Photo by: Gina Coleman/Weedmaps

Vaporizing. This is one of the most efficient ways of decarbing cannabis. When heated at a relatively low temperature, the cannabinoid acids are converted. Continuing to increase the heat will make sure that the maximum amount of THCA is converted into THC, but only to a point. THC's ideal vaping temp is 315 degrees F (157 C); going beyond that may be better for some cannabinoids and terpenes (weed's flavor agents) but you'll lose THC as temps climb. 

Using vape pens. Even more efficient than vaporizing flower is the use of already decarboxylated cannabis distillate found in preloaded vape pens. Since the THCA is already mostly converted to THC and the vaporization takes care of even more, this is an efficient method of taking in intoxicating cannabis. Buy legitimate vape pens from licensed brands and dispensaries to ensure the cannabis oil within contains no harmful ingredients. 

Dabbing. Similar to vaporization, dabbing also decarbs THCA into active THC. Crystalline is the form of THCA most likely to be used for dabbing. It has little flavor or aroma, as most cannabis extractions aim to strip away the terpenes and flavonoids to isolate the cannabinoids. But many producers reintroduce cannabis-derived terpene blends back into the concentrate. Not only does the addition of terpenes improve the flavor, but these distinctively aromatic plant molecules also work together with cannabinoids to produce entourage effects that enhance the therapeutic potential of cannabis.

Baking. For intoxicating homemade edibles, you'll want to decarboxylate the weed before infusing it in butter or oil and you can use your oven to do it. Simply grind your weed, spread it evenly across a baking sheet lined with parchment paper, and bake at 230 degrees Fahrenheit (110 degrees Celsius) for 30-45 minutes. This process will convert most of the THCA into THC.

decarb baking weed
For intoxicating homemade edibles, you'll want to decarb the weed before infusing it in butter or oil.
Photo by: Gina Coleman/Weedmaps

Bottom line

Whether cannabis is smoked, eaten, vaped, or juiced raw, understanding the plant's properties and how they interact with our bodies is crucial in achieving the desired effects and avoiding adverse side effects. Cannabis molecules each have their own benefits and much more research is needed to understand the full scope of what they may offer. 

Frequently asked questions

What are the benefits of THCA?

As mentioned above, THCA could potentially have anti-inflammatory, neuroprotective, and anti-emetic properties. THCA is non-intoxicating (it won't get you high), which some may consider to be a benefit as well. 

Is THCA illegal?

As of 2021, the FDA still lists marijuana as a Schedule I drug. According to the FDA, this scheduling is “due to its high potential for abuse, which is attributable in large part to the psychoactive effects of THC, and the absence of a currently accepted medical use of the plant in the United States.” While the FDA does not mention THCA specifically, it is best to avoid these products in states where THC has not been legalized. 

Will THCA make me fail a drug test?

Whether you smoke a fat blunt and feel heavily intoxicated or juice some raw cannabis and feel a subtle health boost, compounds from both cases may be metabolized into THC-COOH. And most drug tests screen for that metabolite. That said, federal workplaces established cut-offs to help prevent trace amounts from causing false-positive drug test results, according to Mayo Clinic Proceedings from 2017.

What is the difference between CBD and THCA?

THCA is a cannabinoid acid and CBD is a cannabinoid. As such, the two compounds are very different structurally. In practice, THCA may offer some of the same benefits as CBD since they are both non-intoxicating and anti-inflammatory.

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The information contained in this site is provided for informational purposes only, and should not be construed as medical or legal advice. This page was last updated on June 22, 2021.