THCA vs THC: Understanding THC Potency

THCA vs THC: Knowing How to Read Your Weed


Do you know the difference between THC and THCA? Many consumers believe the ‘A’ in THCA stands for ‘active.’ But, that’s not actually true. THCA, or tetrahydrocannabinolic acid, is a non-psychoactive cannabinoid that occurs naturally in cannabis plants. The trick – and the cause of so much confusion – is that THCA turns into psychoactive THC when exposed to sufficient heat. As a result, many labs have struggled to find a reliable method for how to test THC potency levels and label products. So, how can you, the consumer, know that you’re getting the potency you want?

Understanding THC and THCA Potency Testing

In order to understand how your marijuana is labeled, it is necessary to take a quick detour into the two common testing methods.

Gas chromatography (GC) occurs at high temperatures that convert extracted cannabinoids to a gaseous mixture, which is then run through a sort of filter that measures the different cannabinoid levels. One challenge to GC is that the heating process causes some – but not all – of the THCA (and CBDA) to decarboxylate. Decarboxylation is the process where the naturally occurring acid forms of cannabinoids (THCA and CBDA) release carbon dioxide and convert to THC and CBD. Unfortunately, this make GC an ineffective method for testing edibles. It also introduces the possibility that the final test results slightly understate a plant’s actual potency.

Liquid chromatography (LC), on the other hand, occurs at room temperature, allowing labs to test both THC and THCA levels (as well as CBD and CBDA) without the loss that occurs during decarboxylation. The more detailed test results can be beneficial for medical marijuana users, but it creates its own unique challenges that make it less desirable for recreational dispensaries. For starters, LC systems and solvents are more expensive than their GC counterparts, resulting in higher prices for consumers. And, just as important, LC test results can be confusing, increasing the chances a label will be misinterpreted and a marijuana consumer will take more than intended.

THCA-vs-THC-Karing-Kind-Boulder-COLet’s look at a quick example. If a strain is labeled to have 22% THCA and 3% THC, how much active THC will you get with each hit? How can you interpret THCA vs THC? Clearly 3% can’t be right – that’s too low. You might think 22%, since THCA is what converts into psychoactive THC when burned. Or, maybe you’re supposed to add the two numbers together – THCA and THC – giving you a 25% strain. But, THCA isn’t converted to THC with perfect efficiency, giving us another mathematical hurdle before we know the strain’s strength.

A recent investigation into lab testing procedures proposes the following THC formula to calculate total THC when you know the percentages for both THC and THCA.

THCtotal = (%THCA) x 0.877 + (%THC)

So, in our example:

THCtotal = 22% x 0.877 + 3%

That gives us a total THC level of about 22.3%. There. We did it. But, unless you’re a medical marijuana patient, one might argue the slight increase in accuracy isn’t worth the added effort and cost.

How Does Karing Kind Test It’s Products?

At Karing Kind, we use gas chromatography (GC) to test every strain. We provide clear labels and accurate, easy-to-understand total THC and/or CBD potency values to help our customers understand what they’re getting with every purchase. We’re always striving to improve our processes and provide the most accurate information to our customers. If you have any questions about how we test or label our weed, we invite you to stop in and speak with one of our award-winning budtenders.

Boulder’s First Recreational Marijuana Dispensary

Karing Kind is Boulder’s first recreational marijuana dispensary. Our wide selection of organic bud, chemical-free concentrates, and edibles, including our state-low marijuana tax rate, makes us the perfect Colorado cannabis destination.

Karing Kind is located just off of US-36, one mile north of Broadway, open daily from 10am to 10pm.

While we carry a variety of strains, concentrates, edibles, salves and tinctures, inventory and stock levels fluctuate from week to week and month to month. Check our menu and follow us on Facebook and Twitter for an up-to-date list of edibles, concentrates and buds available now.