Weed science

Walk into just about any medical-cannabis dispensary and the shelves will be stocked with labeled jars of ganja. Most of those labels list some basic info: the strain’s name, whether it’s indica- or sativa-dominant, maybe if it was grown indoors or outdoors.

But more and more, Sacramento cannabis providers are including the THC and cannabidiol percentage of their buds. Several dispensaries, including a few in this publication, even promote THC levels in their ads.

And why not? Higher percentages of THC and CBD—the main cannabinoids responsible for pot’s psychotropic and physical effects—mean higher potency.

But it’s natural to wonder: What do those numbers mean? How legit are they? And who determines them?

A spate of laboratories statewide has popped up specifically to educate patients not only about the cannabinoid content of their medicine, but also to make sure what they put in their bodies is safe.

Two local labs—Halent Laboratories in West Sacramento and Sequoia Analytical Labs in Natomas—opened in April. These labs aren’t running on Toys “R” Us chemistry sets, either: They’re using gas and liquid chromatography and mass spectrometer machines, the same pieces of equipment used in the biomedical industry, which require careful scientific training and skillful mathematical analysis.

Lab reps say that type of high-level testing is necessary.

“Anything that goes into the human body or goes on the human body is regulated by the [Food and Drug Administration],” explained Halent’s Kymron deCesare, who also runs lab classes at UC Davis’ chemistry department. But he added that “because cannabis is a Schedule I material, the FDA refuses to address this issue.”

Halent’s other lab guy, UC Davis chemistry professor Donald Land, says three cannabinoids in particular are reported by virtually all testing labs: THC, of interest for its psychoactive effects; CBD, which can alter THC’s effects because it binds to same cell-receptor sites but is also of interest for a myriad of effects, such as relief of pain and spasticity with less psychoactive effect; and cannabinol, where high numbers can indicate that the medicine has been exposed to heat, light or oxygen for longer periods of time.

Land explains that a low CBN number can be important for certain patients. “A lot of the cannabinoid acid compounds in cannabis have anti-inflammatory properties that could help with rheumatoid arthritis, especially pain from arthritis and also in some cases to slow the degeneration caused by the disease,” Land said.

But there are a number of other cannabinoids produced by cannabis plants whose effects are not well understood; Land says Halent currently tests for 15 different cannabinoids in an effort to figure out how they interact.

Here’s how the testing works at Halent: First, when a sample is brought in, they create a chain of custody, which is used to track the sample through the testing process and to make sure it isn’t mixed up with other samples. The sample then goes through a visual and olfactory inspection, then a microscopic evaluation to check for mildew or any foreign particulate matter.

Next, it’s taken to the prep room where it’s weighed, ground and then extracted into an organic solvent. After extraction and filtering, the sample is taken to the instrument room where it’s placed inside a machine for liquid chromatography and mass spectrometer analysis (“LC-MS” in the lingo). That machine spits out a series of graphs that have to be carefully interpreted. Halent then emails the results in a PDF to the client, indicating the presence of toxins and accurate amounts of the components.

They test not only for potency but for safety; pesticides and mold can potentially harm patients with already-delicate immune systems.

Micah Nelson, marketing manager for Sequoia Analytical Labs, said that before opening its doors, dispensaries were sending samples to faraway labs and having to wait weeks to get their results because there were no Sacramento-area testing facilities.

“Basically, the dispensaries would run out of the particular strain before they got test results back,” Nelson said.

Nelson says that in Sacramento, THC levels generally vary from 11 percent on the low end up to the rare 21 percent; the average is somewhere around 16 percent.

Currently, Sequoia works with nine dispensaries, all of them in the Sacramento area. Recently both Sequoia and Halent joined the newly formed Association of California Cannabis Laboratories, which was formed, according to a press release, “to address the growing need for standardization in the cannabis quality assurance industry.”

“We think the ACCL is a really great thing, because standardizing has to be done,” said Nelson. “The numbers don’t mean anything if not everybody is on the same scale.”