Weed edibles are like mystery grab bags right now: It's almost impossible to know how much THC (the main psychoactive chemical in marijuana) or other cannabinoids you're getting out of each gummy or brownie. Take a bite of the wrong chocolate and you could end up immobilized in a giggly stupor — or, perhaps even worse, sober.
Several studies have found that edibles can have significantly more or less THC than their label says. That's a big problem for people who use medical marijuana to handle chronic pain or to treat things like seizures. It can also be dangerous for recreational users who get a stronger dose than they anticipated. Too much marijuana can lead to nausea, psychotic episodes and even a trip to the emergency room.
Part of the problem is that the sugars and additives in these marijuana snacks make it hard for researchers to break them down and study the composition. Additionally, sometimes the label may be accurate, but the THC isn't uniformly mixed into the product, so one serving could be much more or less potent than the next.
However, chemists think they might have found a better way to figure out just how much THC is in these marijuana-infused treats.
The first step is to freeze-dry the edible with ice or liquid nitrogen, said Jahan Marcu, a senior scientist at the advocacy group Americans for Safe Access who helped develop the new technique, during the American Chemical society conference on March 15. Next, mix in a type of powder called diatomaceous earth and throw it all in a blender. The result is a well-mixed weed smoothie from which chemists can easily extract the cannabinoids and analyze them.
However, other experts say it's not a perfect solution. A test that works for all weed edibles may not even be possible, chemist Brian Thomas told NPR. The more ingredients a product has, the more difficult it is to accurately measure cannabinoids.
It's also a problem because different added ingredients can change the way your body reacts to the THC.
"Say you've got a pot brownie with a given concentration of THC. Depending on whether it's made with vegetable oil or butter, your body will absorb the THC in that brownie much faster or much slower," Thomas told NPR.
A better solution, Thomas said, is to limit the amount of edibles available and create a few standardized types with known potencies. Until then, munch at your own risk.