One of the strongest known strains of marijuana in the world is called Bruce Banner #3, a reference to the comic-book scientist whose alter ego is the Hulk. This is probably an appropriate nickname. With a THC concentration of 28 percent—THC is one of the key chemicals in marijuana—Bruce Banner #3 packs a punch. It’s something like five times as potent as what federal researchers consider to be the norm, according to a 2010 Journal of Forensic Sciences paper. High Times marveled in a review: “Who knows what you’ll turn into after getting down with Bruce?”
Yet three years later, another Scottish brewery had whipped up a batch of barley wine called Snake Venom that boasted higher than 67 percent alcohol by volume.
Kahn’s lab uses a technique called liquid chromatography instead. Another potency tester, Denver-based CannLabs, uses a similar method. “Depending on what the sample is—flower, hash oil, hundreds of edibles ranging from ice cream to pasta sauce to seeds—you use different solvents to do the extraction,” said Gennifer Murray, the CEO of CannLabs. “You mix it with a special solvent, basically shake it around, centrifuge it, and then it goes onto the instrument. That’s the liquid chromatograph.”
In other words, it’s difficult if not impossible to classify average potency in a way that can be tracked meaningfully over time. So while there’s almost certainly more super-strong pot available today—if only by the fact that it’s now legal to buy in multiple states—it doesn’t mean that all marijuana is ultra-potent today, which is how the narrative about potency is often framed. There’s also a point at which most strains can’t get much stronger. “Anyone getting a reading over 25, it’s really hard to do,” said Murray of CannLabs. “And then it doesn’t necessarily mean you’re going to quote-unquote get higher. There’s a lot of things that go into the plant—over 500 constituents of the plant that play into this.”
Even without knowing reliably what potency was like in the 1960s and 1970s, it’s reasonable to guess it will increase, says Kahn, of Massachusetts Cannabis Research. “I think the mega-potent strains may soon represent the norm, if not already—the market selects for potency.” But with customers clamoring for the strong stuff, there’s also a question of whether manufacturers are labeling accurately. A Denver Post investigation last year found wide discrepancies between labeling and THC content—in many cases, products advertised a much higher percentage of THC than an edible product actually contained.
More recently, researchers found a THC concentration that “gradually increase[d]” from 1993 to 2008, according to a 2010 paper in the Journal of Forensic Sciences. And despite testing limitations, researchers have always maintained potency is likely trending upward. But they’ve also always been upfront about the limitations to their findings: “The change in cannabis potency over the past 40 years has been the subject of much debate and controversy. The [Potency Monitoring] program has strived to answer this cannabis potency question, while realizing that the data collected in this and other programs have some scientific and statistical shortcomings.”
This is human nature. Or maybe it’s just capitalism. One person makes a superlative product, which prompts the next person to best them. Given the opportunity to try something extreme—the biggest, the strongest, the best, the craziest—plenty of people will go for it. But most people don’t pick Snake Venom as their typical pint. And Bruce Banner #3 probably is not representative of the average joint.
As marijuana goes increasingly mainstream—and, crucially, develops into big (and legal) business—more super-potent novelty strains are likely to crop up. Bruce Banner #3 is the marijuana industry’s answer to The End of History, an ultra-strong Belgian-style ale that the Scottish beer-maker Brewdog made in a specialty batch—which was then served in bottles inside taxidermied squirrels—in 2010. Its alcohol by volume was 55 percent. That’s way, way stronger than most beers. “It’s the end of beer, no other beer we don’t think will be able to get that high,” James Watt, one of the founders of Brewdog, told me when I visited the Brewdog headquarters in Scotland in 2010.
Ultimately, researchers have found a “large variation within categories and over time,” they wrote. That’s in part because sample sizes have fluctuated. (In the 1970s, researchers assessed anywhere from three to 18 seizures a year. In 2000, they analyzed more than 1,000 seizures.)
How incomplete government data encourages a pervasive pot myth