Back to blog

THC Vs. THCA: How to Read Cannabis Lab Results

Back to blog


Curious about cannabis lab results? Not sure how to read them? You’ve come to the right place. If you find it tricky to understand how to read THC vs. THCA lab results, you’re in good company. Many people like knowing that their cannabis has been third party tested by verified labs because it validates the safety and efficacy of the products. Still, some might not be sure how to read these lab results.

Educated consumers should understand what is in their products. This goes for all products, not just CBD, THC, and THCA. With that said, some labels and lab results are easier to read than others. Reading and fully comprehending THCA lab results requires some knowledge of math – there’s just no getting around it. Don’t worry, though – you don’t need to be a mathematician to enjoy THC and THCA.  Having a general idea of what to look for will suffice. If you really want to get into the finer details of THC vs THCA, we have a formula for that as well. 

What is the Difference Between THC and THCA?

Understanding how to read cannabis lab results starts with knowing the difference between THC and THCA. Tetraydrocannabolic acid (THCA) is the precursor to THC. While the two cannabinoids have similar structures, there is one stark difference: THCA has an extra carboxyl group that THC does not. This one detail may seem small, but it makes all the difference in whether or not the compound will deliver psychoactive effects. Having an extra carboxyl group means that THCA is not psychoactive in its raw state and will therefore not get you high.

Once it is exposed to heat and light through decarboxylation, however, THCA loses the extra carboxyl group and effectively becomes THC.

How Does THCA Become THC?

We mentioned earlier that decarboxylation transforms THCA into THC. Decarboxylation is the chemical reaction that results from exposure to light and heat. When put in the right environment (i.e., a decarboxylator, the oven, smoking/vaping, etc.), the extra carboxyl group from one substance (in this case THCA) gets removed, therefore activating the psychoactive compounds in the cannabis plant.

There are various decarboxylation methods, some of which include:

  • Using a decarboxylator (sous vide method)
  • Decarbing THCA in the oven
  • The mason jar method for decarboxylation
  • Making cannabutter

How do you Read THCA Lab Results?

With this knowledge as a foundation, there is still some confusion when it comes to reading cannabis lab results, particularly surrounding THC vs THCA. How do you determine THCA content? How can you know how much THC will be derived from THCA during the transformation process? Some of the uncertainty about total THC is due to the lab techniques used and the separation methods, which are gas chromatography (GC) and liquid chromatography (LC). Earmark these terms, as we’ll circle back to them in a bit.

What is Total THC?

Reading cannabis lab results and deciphering the total THC content of a product means you need to get the real potency value of the substances. This is where the math calculations come in. The formula to calculate THCTOTAL is:

THCtotal = (%THCA) x 0.877 + (%THC)

Knowing the total THC content will help you understand how strong a certain strain of THC vs. THCA is.

What to Consider When Reading Lab Results for THC vs. THCA

We mentioned the separation methods GC and LC earlier; now is when they will come back into play. Knowing how to read cannabis lab results correctly is important for understanding how strong the product you’re taking will be. Additionally, GC does not work for THC edibles, which is why many labs have switched to the LC method.

Seeing more than one THC percentage on LC cannabis lab results is a good thing, as it indicates both the THCA and the THC content. Having these percentages on the label means the lab has taken all of the necessary steps to ensure clarity and transparency. In instances where labs use the GC method (for non-edibles), seeing one THC percentage will suffice, as this will indicate the total amount of THC.

Reading cannabis lab results can be complicated, even for the most experienced of users. Need more insight on finding out what a high THCA percentage is? We have you covered.

Whether or not you choose to go through all the calculations of deciphering THC vs. THCA for the total THC content, when you purchase from Black Tie CBD, you can be sure that everything you’re getting is high-quality and third-party tested.  Some of our bestselling THCA flowers include:

We also offer THCA concentrate in a variety of forms. Shop now to find your perfect strain.