Labels like indica, sativa and hybrid—commonly used to distinguish one category of cannabis from another—tell consumers little about what’s in their product and could be confusing or misleading, suggests a new study of nearly 90,000 samples across six states.

Published May 19 in the journal PLOS One, the research constitutes the largest analysis to date of the chemical composition of marijuana products. It finds that commercial labels “do not consistently align with the observed chemical diversity” of the product. The authors are now calling for a weed labeling system akin to the Food and Drug Administration’s “nutrition facts panel” for food.

“Our findings suggest that the prevailing labeling system is not an effective or safe way to provide information about these products,” said co-author Brian Keegan, an assistant professor of Information Science at the University of Colorado Boulder. 

2022 marks the 10-year anniversary of the legalization of recreational marijuana in Colorado and Washington, the first two U.S. states to permit adult use. The industry has grown into a multi- billion dollar one, in which sativa strains are generally associated with an energetic high while indica strains are associated with a relaxing effect. 

Yet no standardized labeling system exists.

Commercial strain names like Girl Scout Cookies and Blue Dream give consumers the impression that if you buy it in one place, you’ll get the same product or effect if you buy it elsewhere.

While marketers generally must disclose dosage of the psychoactive compound THC (tetrahydrocannabinol) and CBD (cannabidiol) on the label, they are not obliged to include information about other compounds, including terpenes, which can influence not only the smell but also—via a hypothesized synergistic effect called the entourage effect—the way a product makes you feel. 

They are also free to name their product what they want.

To get a sense of how similar same-named products are, Keegan teamed up with Nick Jikomes, director of science and innovation for the e-commerce cannabis marketplace Leafly.com. They applied data science tools to a massive database of chemical analyses Leafly has compiled from cannabis testing centers.

After sorting about 90,000 samples from six states according to their cannabinoid and terpene make-up, the researchers found products do tend to fall into three distinct categories: Those high in the terpenes caryophyllene and limonene; those high in myrcene and pinene; and those high in terpinolene and myrcene.

But those categories do not neatly correspond to the indica, sativa and hybrid labeling scheme.

“It is likely that a sample with the label indica will have an indistinguishable terpene composition as samples labelled sativa or hybrid,” they wrote.

How biochemically similar are products with the same commercial names?

That depends on the strain, the study found.

Some strains, such as one called White Tahoe Cookies, were surprisingly consistent from product to product, while others, such as one called Durbin Poison, were “consistently inconsistent.” 

As consumers increasingly use cannabis for specific purposes, including health purposes, precision in labeling will become even more critical, Keegan said.

He envisions a day when products are categorized based on a more comprehensive understanding of their chemical make-up and labeled with details on not only their THC and CBD, but other compounds.

“It’s like if your cereal box only showed calories and fat and nothing else,” said Keegan. “We as consumers need to be pushing for more information. If we do that, the industry will respond.”

Read this article about misleading food labels.