Ever wonder how dispensaries determine the levels of THC, CBD or other cannabinoids in your favorite strain? Each plant—even those from the same batch of seeds—can have a different chemical profile. The process of separating and identifying a plant’s chemicals requires testing conducted at state-of-the-art laboratories.
Twenty years ago advocates for cannabis legalization would fantasize about government-mandated marijuana testing. One of the arguments against cannabis legalization at the time was that the drug was unsafe because users didn’t know what compounds were present in the black market weed they bought. There were even stories—most were propaganda, of course—about joints “laced” with other substances, like PCP or formaldehyde. One of the counter-arguments—in favor of legalization—was that regulation and government oversight would make consumption safer.
These days, thanks to the ever-growing legal cannabis market, there are labs that do business solely with marijuana companies. These labs can determine the profile of a strain and give patients a clear idea of what it is they’re buying. It’s a literal dream come true.
When a sample is sent to a lab, it’s entered into a digital inventory system that tracks it throughout the process. The sample is inspected through a high-magnification microscope before being frozen in dry ice and cryogenically ground into a fine powder that can be dissolved completely in a solution. The solution-laden sample is then put into a vortex, where it is agitated to evenly spread out the contents of the sample. The shaken-up sample is then placed in a sonic bath, where it is further agitated through applied sound energy. This process separates the cannabinoids from the plant matter in the solution.
The sample is then sent through a centrifuge that spins the sample at high speeds to separate the solution from the useless plant matter, allowing technicians to extract a clean sample. The solution is diluted and placed into a liquid chromatograph, a piece of equipment that can separate a sample into its individual parts.
The sample is also tested for pesticides by running it through a mass spectrometer. In addition the sample is tested for mold and bacteria.
The results of all of these tests are ultimately put together in a lab report that is sent to the dispensary and used to make labels.
New Mexico law currently requires dispensaries to note a product’s THC and CBD volume on the label, but some advocates are calling for more transparent practices that could include other cannabinoids and terpenes as well. It’s unclear if the state’s Department of Health is likely to make those labeling rules more stringent.
One pragmatic problem with adding more labeling requirements is space. There are many different compounds found in any given sample of marijuana, and only so much label space on a bottle. Environmentally conscious dispensaries are already put in an awkward position when they try to find a responsible container to hold single grams of flower and attach a label that’s big enough to have all the important information listed.
The answer might be market-driven, though. A few dispensaries already list CBN or CBG content alongside THC and CBD on their labels as a courtesy to customers. If enough patients make it clear that they want more detailed cannabinoid reports, then the producers will likely find a way to provide it. They wouldn’t even need to put the reports on individual bottles; dispensaries could just keep a publicly available list handy.
One thing is for sure: Clarity is always appreciated by patients, and transparency can go a long way toward making them happy.