Cannabis is becoming a more popular natural health solution. But the market is still highly unregulated. Many companies are not entirely honest about the potency and purity of their products. Often, THC potency does not match label.

So how bad is the issue? A recent study reveals that it may be worse than you think.

Study Reveals THC Potency Does Not Match Labels

Researchers at the University of Northern Colorado tested cannabis samples from dispensaries statewide. They found that in most cases, THC potency does not match labels.  

The study marked the first of its kind to examine the potency of commercially sold cannabis. It emphasized how the lack of industry regulation could be leading consumers to buy products that are not as potent as advertised.

“I don’t believe what’s on the label. We just don’t have enough information for consumers about whether or not you can trust what’s being produced,” said Mit McGlaughlin one of the study’s authors and a University of Northern Colorado professor of biological sciences.

What Was Involved in the Study Finding THC Potency Does Not Match Labels?

The study that revealed THC potency does not match labels involved 23 samples of cannabis purchased from 10 dispensaries in Garden City, Denver, and Fort Collins, CO. Each sample was tested to measure its THC content.

18 of the 23 samples revealed cases of THC potency that do not match the label. In some products, the potency was 40% to 50% less than advertised. On average, potency was 23% less than the amount listed on the bag.

Only five of the bags had a potency that was close to what was advertised.

“These results make it clear that consumers are often purchasing cannabis that has a much lower THC potency than is advertised,” the study authors noted.

Is Cannabis Regulated?

doctor hand hold and offer to patient medical marijuana and oil.

The issue of THC potency does not match the label largely due to a lack of federal regulation. Although cannabis is legal in 21 states and D.C., it is still illegal under federal law. Therefore, regulations vary from state to state.

“We have a hodgepodge of rules and regulations within each state,” said McGlaughlin. “It’s really hard to have to do that on a state-by-state basis.”

Many marijuana companies send their products to labs for third-party testing. The results show what’s in the weed and the content of each component.

However, testing can be inaccurate. For example, cannabis buds in one sample can have different levels of potency. While the aim is to get a sample that is representative of the entire batch, this doesn’t always happen.

Different labs also have different ways of running their tests which can lead to varying results.

It’s also possible that companies may forego testing if they are not legally made to do so. (Some states enforce third-party testing, while others do not.) Or they may fudge the results.

In the state of Colorado, cannabis must be third tested for potency and contaminants. It’s unclear as to why the products in the study showed a discrepancy.

Dispensaries often charge more for products with a higher potency. Many claim their products are more potent than they are so they can raise their prices.

“It’s just kind of a mess right now,” said Schwabe, the director of research and development for a New Jersey cannabis farm. “And really, the folks who are at the short end of the stick are the consumers.”

How Much THC is in My Marijuana?

Scientist researcher examining genetically modified green leaf under microscope. Biologist engineering observing organic gmo plants while examining in microbiology food laboratory.

When THC potency does not match labels, people can’t be sure of how much marijuana they are consuming. This can lead to dangerous situations.

In February, a medical marijuana patient in Arkansas sued a cannabis farm and testing lab for selling products where THC potency does not match labels. Two California residents filed a similar lawsuit in October about the false advertising of THC potency in pre-rolled joints.

“This is not getting what they paid for. This is not just a Colorado issue; this is a national issue,” said Schwabe.

And false advertising regarding marijuana potency is not the only problem. Companies may also be dishonest about the product ingredients.

For example, a 2021 clinical trial showed that people who thought they were taking a product with CBD, a cannabis component that does not have psychoactive effects, were taking THC.

“That was a really scary experience for them,” said Jodi Gillman, the director of neuroscience at the Center for Addiction Medicine at Massachusetts General Hospital.

Schwabe and McGlaughlin conducted a separate study on the smells of different weed strains that also showed THC potency does not match labels.

The researchers sent cannabis samples to a private lab. The lab staff dissolved the cannabis buds through a solution and ran the resulting liquid through a chromatography machine that separated the plant components according to molecular weight. This helped them determine the THC concentration.

Although the concentration of THC can fall as you travel from the top to the bottom of the cannabis plant, Schwabe doesn’t believe it’s enough to account for the discrepancies. She also notes that there has been a rise in THC content in modern plants, but she doesn’t believe it’s “as inflated as we have been led to believe.”

THC can break down over time, especially if it isn’t stored correctly. But when it degrades, it converts to cannabis oil which “was not observed in sizable quantities in the samples used in the study, indicating the lower potency in the observed versus reported values were not due to age or poor storage conditions,” the researcher stated.