Thanks to advances in technology and improved growing methods, the THC content in some of today’s cannabis (e.g. concentrates) are over 50% THC, with some as high as 80% or above.
Researchers still don’t know the full effects of what high levels of THC do to the mind and body, especially the developing mind and body. But higher levels of THC may result in more harmful reactions for new users.
Marijuana potency has increased over the past few decades. In the early 90s, it’s reported that the average tetrahydrocannabinol (THC) level in weed was around 3.7%. In 2013, this percentage jumped to 9.6%.
By now, you’re probably wondering what caused the spike in potency. And not only that, but how do people determine the percentages of THC in the first place.
In this article, you’ll learn the answer to both of these questions.
Factors that determine marijuana potency
Some factors that affect the potency of marijuana include:
- Growing climate and conditions
- Plant genetics
- Harvesting and processing
- Desire by small growers to maximize profit.
The time at which the cannabis plant was harvested also affects the THC level in your flower. In addition, female plants have higher THC levels than their male counterparts.
How to test THC levels
Currently, there is no industry standard for calculating the total THC level in cannabis. So different cannabis producers and testing facilities calculate this percentage level using different techniques.
But to get a basic understanding of how this level is determined, you must first know the difference between THC and THCA.
Without getting too sciencey, THCA is a non-intoxicating compound that can be converted into THC through decarboxylation. Decarboxylation occurs with the introduction of a heating mechanism. In the case of cannabis, these mechanisms include lighters, vaporizers, and ovens.
Most cannabis products sold legally in the US are required to be tested and labeled for THC content. Many labels will have ‘Potency Analysis’ numbers listed out and often include measurements for THC, THCA, and Total THC.
The Total THC refers to how much THC will be present as a percentage of dry weight after the THCA has been converted into THC. This amount is usually around 20%, which is lower than the THCA level.
This percentage is calculated using methods that are difficult to understand or reproduce unless you have experience in the field. But if you’re interested, you can find the calculation methods here.
What does this mean to me as a consumer?
The THC level indicated on the label is usually on the low side (at around 1.0%). This is because, at this point, the plant contains mostly THCA. Before being introduced to a heating mechanism, most of the THC remains in its inactive state. Because of this, the THCA levels indicated on the label are higher (at around 24%).
One final thing to mention about the THC level in your cannabis is that it partially depends on the consumption method you choose.
According to research by Dr. Rudolf Brenneisen at the University of Bern in Switzerland, the heating of cannabis at 200 degrees Celsius [which is possible through the use of vaporizers] for 5 minutes results in almost 100% decarboxylation of THCA to THC.
On the contrary, “the burning of cannabis at higher levels [i.e. by using a lighter or torch] will probably result in a higher decarboxylation rate, but also the production of potentially harmful products.”
Now that you know what factors determine marijuana potency and how this potency is measured, it’s important for you to understand that the levels on your cannabis labels are not always accurate.
Because people use different calculation methods, it’s best to assume that the total THC level is less than what’s on your product. Exactly how much will depend on the factors listed above.
For those of you concerned with THC levels in the body, it’s important to note that detectable amounts of THC can remain in the system for several days to weeks following consumption, depending on potency and amount consumed.
And if you’re new to cannabis and THC levels in general, it’s always advised that you ask for recommendations from your budtender.