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Colorado’s Marijuana is 3X Stronger (and a Little Dirty)


marijuana(HealthDay News) — New lab tests on Colorado’s legal marijuana suggest that the state’s weed supply is more potent than ever, and also a little dirty.

For over a year, Coloradans age 21 and up have been able to buy recreational marijuana from state-regulated dispensaries. As part of the experiment, several labs have been certified to monitor samples from the state’s burgeoning pot industry.

One of those labs is scheduled to report its initial findings on Monday at the annual meeting of the American Chemical Society, in Denver.

Those tests revealed one pattern that was somewhat surprising — namely, the pot’s high concentrations of THC, according to Andy LaFrate, president of Denver-based testing firm Charas Scientific.

THC is the compound that gives marijuana users a “high,” and on average, the pot in Colorado’s retail supply is 30 percent THC. According to LaFrate, that’s more than triple the THC level typically found in street marijuana a few decades ago.

Is that concerning? “I don’t think so,” LaFrate said. “Especially when you’re talking about smoking.”

However, he added, high potency can be an issue with marijuana-infused “edibles.” People can easily overdo it with ingested pot because its effects aren’t as immediate as when it is smoked. LaFrate noted that Colorado has passed new regulations targeting edible marijuana — including potency restrictions and stronger child-resistant packaging.

LaFrate’s lab also found some contaminants in retail pot samples, including fungus and the chemical butane, which is used in making marijuana extracts. Whether that’s any cause for worry, however, is unclear.

“Some contamination is inevitable,” LaFrate said. “Is there a threat from the contaminants we found? It’s hard to say. But if you’re smoking, these [substances] will be inhaled into the lungs.”

Finally, the lab found that pot samples contained little to no cannabidiol, or CBD — one of the marijuana compounds believed to have medicinal properties.

That’s not surprising, LaFrate said, given that the point of recreational pot is to get high. But, he added, “there is a decent number of people buying retail marijuana who want some medicinal value.”

So those folks should be aware that what they buy could be devoid of CBD, LaFrate said.

Paul Armentano, deputy director of the nonprofit NORML, saw no surprises in the findings.

“It is well known that Colorado possesses two separate markets for [marijuana] — one for medical consumers and one for retail consumers,” said Armentano, whose Washington, D.C.-based group advocates for legal marijuana use.

So it’s “hardly surprising,” he said, that the state’s retail pot would be high in THC, but low in CBD.

And, Armentano said, concerns about high THC levels seem “largely misplaced.” People seeking a high will probably smoke less, because it will take less higher-potency marijuana to achieve a high.

As for contaminants, Armentano said, “obviously one wants consumers to be able to obtain a product of consistent quality and safety.” And that’s why ongoing quality testing is crucial, he added.

“Further regulatory oversight may be needed in order to assure that consumers are presented with a product of consistent and acceptable quality,” Armentano said.

That may eventually happen, LaFrate speculated. Still, he said, “even though we did find these contaminants, I think overall the supply is very safe.”

Along with Colorado, three other states — Alaska, Oregon and Washington — and Washington, D.C. currently have a legal marijuana market.

By Amy Norton, HealthDay


NORML keeps track of state marijuana laws.

Copyright © 2015 HealthDay. All rights reserved.


  1. Why don’t you write an article about contaminated water in beer, and all of the prescriptions in the water from peoples urine.

    BTW search Cannabis patent: US6630507

  2. We have zero chance of regulating potency or purity in an unregulated market, so this is yet another reason to legalize and regulate it.

    There was plenty of strong cannabis available years ago, sensimilla. It is simply a matter of preventing the female plants from being pollinated so they do not get seeds. Yes there is less “ditch weed” around on average. This is a good thing since people throttle their intake and less plant matter needs to be combusted and inhaled for the same desired effect. With legalization we get the added benefit of product potency listed on the container, just as with liquor proofing. Part of the reason THC content has risen? Prohibition. It is more profitable to sell stronger cannabis (it uses less space for the same level of effect).

    Even the cheapest “ditch weed” from decades ago was around 1-3% THC (the cannabinoid that creates the ‘high’) whereas even the strongest varieties today are only in the 20’s, not world changing. Hash has been around for decades and can be over 70% THC. The NIDA-sponsored Marijuana Potency Monitoring Project reports that less than 10 percent of DEA seized marijuana samples are above 15 percent. Less than 2 percent of marijuana seized from the domestic market contains more than 20% THC. Decades ago the FDA approved a 100% THC drug called Marinol which is considered safe. It is listed in Schedule III, however it is expensive and not as effective as the natural plant which contains dozens of other therapeutically active compounds.

    “Increased potency has been observed in some countries, but there is enormous variation between samples, meaning that cannabis users may be exposed to greater variation in a single year than over years or decades. Claims made in the public domain about a 20- or 30-fold increase in cannabis potency and about the adverse mental health effects of cannabis contamination are not supported currently by the evidence”
    McLaren et al. Cannabis potency and contamination: a review of the literature. Addiction. 2008. Review.

  3. Love this study. Had pot not been legalized, could you imagine this type of research being funded?

    Also, incidentally, the results jive with what middle aged people smoking a joint for the first time in decades have found anecdotally – it’s a different type of pot these days, more potent.

  4. Just stop with the ridiculous propaganda, please. Stop wasting our tax dollars and police time on this, it’s stupid. Everyone knows that prohibition is the only thing dangerous about marijuana. If you support prohibition, then you support the cartels. It’s that simple.

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