Weed buyer beware: THC inflation is getting out of hand
Something is rotten in the legal cannabis industry. In every legal state, the THC percentages printed on product labels are becoming less reliable. These numbers are too often inflated—sometimes drastically. What’s worse: This is largely due to fraud rather than mere incompetence.
Not every lab is doing it. But too many are. THC inflation occurs when testing labs produce artificially high THC percentages for products.
Labs are pressured to do this by producers, who want higher THC percentages in order to sell their merchandise at the highest possible price. Producers engage in “lab shopping,” sending samples to multiple labs, seeing who provides the highest THC values. From there, they can hold labs hostage by threatening to take their business elsewhere if they’re not given the numbers they want.
Consumers taking legal action
Consumers are the losers in this game, and some of them are getting fed up. In Arkansas, three medical marijuana patients recently filed a class action lawsuit against a local cannabis testing lab. The plaintiffs allege that the lab “intentionally inflates the amount of THC in its customer’s flower” for at least three cannabis producers in the state. Nothing has been proven, but the mere fact of the lawsuit’s existence—the idea that consumers would sue a lab, not the product manufacturer—gives us an indication that something’s amiss in the industry.
To those working within the cannabis industry supply chain, a clear sequence of cause-and-effect is at work. As Nick Mosely, CEO of Washington cannabis testing lab Confidence Analytics, put it: “Labs are motivated to do this to gain market share. The labs’ customers pressure them to foster potency. This pressure comes from the retail side, and ultimately originates from consumer demand for higher label numbers.”
Any cannabis retailer will tell you that potency, defined strictly in terms of THC levels (or CBD, for non-infused products), dictates both how quickly products sell and the price per gram. This has also been formally measured in the scientific literature.
Why is this happening?
Many cannabis consumers perceive higher potency products to be better. It’s simple, commonsense thinking. If two products are the same price but one is labeled 17% THC and the other 22%, the latter must be a better deal—more bang for your buck.
The ironic end result of this purchasing pattern is that consumers are duped into buying products that actually have lower THC levels than what’s advertised.
A brief history of THC inflation
THC inflation is an open secret within the industry, present since the inception of state-legal cannabis programs. Leafly has covered this multiple times over the years, including an investigation into Peak Analytics, a Washington testing lab, back in 2017.
The story is more or less the same each time. One or more labs start pumping up the THC numbers. Word gets around. Producers flock to them. The labs conducting honest business suffer and complain to regulators. Sometimes the cheating lab is formally investigated and suspended, but oftentimes not, or only after a lengthy stretch of time. The problem repeats ad infinitum as other labs succumb to economic incentives.
Dr. Chris Hudalla, Chief Science Officer of ProVerde Labs in Massachusetts, says things have reached a point of national crisis. “As the industry has gotten bigger and more competitive, the problem is only getting worse, not better. There is more product on the market, pushing prices down. Higher THC makes it easier to sell, fetching higher prices. At the same time, the number of labs competing for testing has exploded, making it harder for labs to survive.”
Well documented by data
THC inflation is now well-documented in the scientific literature. Back in 2018, I teamed up with Micahel Zoorob, then at Harvard, to analyze publicly available lab data from Washington. Our study showed clear indications that some labs consistently produced higher THC levels than others.
In 2021, Dr. Zoorob published another study of testing results from both Washington and Nevada, showing that potency data displayed an odd statistical pattern. There was a preponderance of samples with greater than 20% THC, much more than expected based on natural variation in THC levels. This pattern was visible in the aggregate but seemed to be driven by specific labs consistently producing an overabundance of samples with >20% THC.
“In both Nevada and Washington, an unusually high frequency of flower products report THC concentrations just higher than 20% THC (and an unusually small frequency report just below 20% THC). This discontinuity is evident for some, but not all, labs; and it persists even when examining products from the same growers.”
While it’s known that producers sometimes adulterate samples to pump up their potency numbers, Zoorob’s analysis indicated that the anomalous patterns are, “better explained by laboratory-level differences.”
A curious jump up to 20% THC
Zoorob has seen similar patterns in Oregon, whose data he’s examined for a forthcoming article: “I don’t believe this is an isolated phenomenon, as the underlying causes are at play across states.”
The ultimate economic driver of this problem may be the way consumers spend their money, but it’s unscrupulous labs who supply the inflated numbers to meet that consumer demand.
How cannabis testing labs inflate THC levels
I asked several cannabis testing experts how labs inflate THC levels. Due to the technical complexity of laboratory testing, “the possibilities are too numerous to list,” as Patrick Trujillo, technical director for Chem History in Oregon, told me. Nick Mosely, head of Confidence Analytics, described some of the techniques used by other labs:
“Praxis lab in Washington was found to have their CSO changing the numbers in the night, electronically. Other labs have their ‘finger on the scale’ by adjusting dilution or extraction volume subsample weights, balance or instrument calibrations, or subsample masses. Other labs achieve inflated THC numbers with bad chromatography.”
While outright data manipulation happens, subtler techniques can be used to inflate THC levels. Dr. Hudalla explained how labs can inflate numbers by manipulating moisture content: “They can dry samples further to inflate reported THC values. Many states do not require reporting of the moisture content with the potency values, so it is hard to put the reported potency in context.” A dryer sample means lower moisture content, and therefore a higher THC percentage. (Cannabis connoisseurs will also tell you that moisture is an important marker of quality. Nobody wants to smoke bone-dry weed.)
Lack of tough state regulation
If the problem is so widespread, what are state regulators doing to police labs engaged in these deceptive practices?
The ubiquity and persistence of THC inflation indicates that regulators are not doing very much to reign in the problem, or that their actions are impotent. While bad actors are sometimes caught and suspended—Washington State officials revoked the license of Praxis Laboratories, effectively killing the company— that hasn’t prevented THC inflation from becoming endemic. Following suspension, the same bad actors sometimes just re-merge under a new guise.
When I asked Patrick Trujillo about what regulators are doing about this issue in Oregon, he didn’t mince words: “OLCC and the Oregon Health Authority are only interested in regulations that generate tax dollars. We have told the Oregon state regulators about this and have been continually told, ‘We don’t have the authority so our hands are tied.’ Regulators know that high potency sells, and products that sell generate tax revenue. The problem always comes back to money.”
Dr. Hudalla had similar things to say about Massachusetts regulators: “I have not seen any action to address this issue. The state regulators have publicly acknowledged that they are aware of the issue, but that is as far as I have seen them go. We have seen no action.”
If effective regulatory oversight can’t be counted on, what can we do?
Arming consumers with information is a first step. Lab-based THC inflation is almost entirely driven by consumer demand—or rather, the misguided consumer fixation on THC content. Nearly every true connoisseur will tell you there are so many more aspects to cannabis quality beyond THC.
So where does this fixation on THC come from?
The psychology of THC fixation
There are two factors at play here. The first is simply that THC is widely known as the main psychoactive cannabis ingredient. Almost all consumers are aware of this and comparatively few know or care about other things, such as terpenes or the biphasic effects of THC.
The second factor is the natural human tendency to focus on nice, “round” numbers. We like multiples of five and ten. Marketers have long taken advantage of this. It’s why so many things are priced at $19.99. Even though it’s trivially different from $20, it feels like a good deal because it’s not even twenty bucks.
The psychology is similar for THC content. Twenty percent is a magic number. It feels like a nice cutoff for “potent” weed and it’s just above the true average THC content of cannabis flower (17-18%). In 2022, most consumers want weed with THC levels above that threshold, which is why there’s so much pressure placed on labs to inflate the numbers by a few points. For a more thorough explanation of this and how it relates to the patterns we see in lab testing data, watch this online talk I gave in 2021:
Work the system to score good deals on weed
As a consumer, there is a way to hack this dysfunctional system.
Weed with <20% THC doesn’t sell as quickly, so it’s often placed in the “bargain bin” at dispensaries. This is often high-quality weed that’s been marked down because it hasn’t sold, often just because it has “low” THC content.
Find the bargain bin and look for flower with a dense coating of visible trichomes—the small “crystals” dotting properly grown cannabis. If there are lots of big, juicy trichomes, it’s a visual proxy for quality. In my experience, you can often find good cannabis in the bargain bin for no other reason than it “only” has 14-17% THC.
What is Leafly doing about it?
Around 2018, Leafly became interested in working with testing labs in order to bring information about the cannabinoid and terpene content of cannabis products to consumers. Given the unfortunate state of lab testing, we knew data quality would be an issue. Using statistical methods developed based on the published research on lab testing, we devised the Leafly Certified Labs program.
To become a partner, labs must first submit anonymized data, which we scrutinize for… interesting patterns. The unfortunate result of doing things this way is that we reject roughly 75% of the labs we screen.
By aggregating data across the labs we partner with, we can determine the potency levels and terpene profiles associated with cannabis strains and products, based solely on testing data that doesn’t show signs of inflation. This data then feeds into our strain database and can be used in recommendation algorithms.
The main problem here is that there is currently no good way for us to tell consumers which specific products come from these labs–which ones have the most trustworthy labels. The best you can do today is insist that your local dispensary show you the Certificates of Analysis for the products you’re interested in. If any come from our certified lab partners, those products are much more likely to have accurate labels.
Will THC inflation get reined in?
THC inflation has spread and persisted in every single cannabis market in the US despite the existence of regulatory bodies in every state. One can hope for federal legalization, which in theory would set the stage for an overarching system of regulation and enforcement, but I’m not holding my breath.
The best advice I can give is to educate yourself. Remain aware of how the industry actually operates. Learn to use your primary senses to identify quality and don’t take THC potency as the sole indicator of product value.
If you’re a consumer concerned about THC inflation, one simple thing you can do is make a fuss about it. Contact your state cannabis regulators. Call or send an email. Annoy them. Flood their inboxes. Here’s the contact information for a few:
To learn more about Mind & Matter and listen to the podcast episodes that inspired this article, visit this link.
Nick Jikomes, PhD
Nick is Leafly’s Director of Science & Innovation and holds a PhD in Neuroscience from Harvard University and a B.S. in Genetics from the University of Wisconsin-Madison. He is the host of a popular science podcast, which you can listen to for free at: www.nickjikomes.com. You can follow him on Twitter: @trikomes
View Nick Jikomes, PhD’s articles
By submitting this form, you will be subscribed to news and promotional emails from Leafly and you agree to Leafly’s Terms of Service and Privacy Policy. You can unsubscribe from Leafly email messages anytime.
Post a comment: