Researchers Create New Cannabis Categorization System For Medical Use

Researchers from the University of New Mexico (UNM) have developed a new system for labeling and indexing cannabis flower, which they say is more useful to consumers than relying on strain names or commercial labels alone.

The new indexing system, described in a paper published in the Journal of Cannabis Research, was constructed based on an analysis of anonymized data gathered by the Releaf App, a popular app for recording cannabis use sessions and its subsequent effects on the mind and body.

In a proof-of-concept study reported in the same research paper, the UNM researchers also showed that unique cannabis chemovars indexed under the new system clearly differed in their impacts on medicinal users’ health. Classifying cannabis flower according to this new system may give patients and caregivers a more effective way of identifying and distinguishing preferred chemovars, the researchers say.

New categorization system hinges on terpene content

In the Releaf App, medical cannabis users can rate and record their symptoms before and after using their cannabis product of choice, as well as input the exact THC and CBD levels reported for the product. The app also gives users the option to record even more specific compositional data, such as the terpene content of the flower, if it is available.

For this new analysis, the UNM researchers looked at anonymized Releaf App data submissions from 204 users covering more than 6,300 unique cannabis use sessions that included patient outcome reports and detailed terpene and cannabinoid label data.

Using this data, the researchers constructed a new indexing system, the Vigil Index of Cannabis Chemovars (VICC), named after the study’s lead researcher, Jacob M Vigil. The VICC is a four-character chemovar code that broadly describes the primary and secondary terpene levels, as well as THC and CBD levels, in a given sample of cannabis flower.

The first two characters of each code indicate which two terpenes are present in the highest concentration. In addition, between one or three superscript ‘+’ signs could be added after one or both letters, indicating that terpene is present in high amounts, between 0.5 to 3% dry weight.

The third and fourth characters in the coding system refer to the relative levels of THC and CBD respectively in the cannabis, measured on a scale of 1-8 for THC and 0-8 for CBD. As an example, the full index code for a chemovar containing high levels of terpinolene, lower levels of limonene, and a THC level of around 20% with no detectable CBD would be “T⁺L60”.

The problem with cannabis strain names

Cannabis strain names are an incredibly effective marketing tool. After all, who wouldn’t be intrigued by a product named 24K Gold or Grapefruit Durban? Unfortunately, an effective marketing tool does not necessarily translate to an effective way for consumers to distinguish and discuss the plethora of products that are up for consideration.

According to recent studies, much of the cannabis being sold under different strain names actually barely differs in terms of cannabinoid profile and composition. More recently, experts have even suggested that consumers should ignore the growing marketing push towards high-THC cannabis strains, and should instead rely on their sense of smell if their priority is seeking out a pleasant high.

For medical cannabis users who are seeking out predictable and reliable drug effects, navigating the thousands of cannabis strain names available in dispensaries can be overwhelming. Having an indexed system that efficiently imparts information about the major cannabinoids and terpenes present in a strain can empower users to make more informed choices about what products they are using.

“Due to the modernization and hybridization of the cannabis plant, strain names are largely irrelevant and nothing more than a marketing strategy used by brands and retailers to try and sell products,” said Tyler Dautrich, chief operating officer of Releaf App’s parent company MoreBetter, in a statement. “This publication provides a proof-of-concept of a more accurate and legitimate way to classify cannabis flower and better inform [the] consumer.”

Chemovar codes highlight relevant differences in health outcomes

It is not just consumers who might be interested in a cannabis index system; researchers can also benefit from a system that allows for the grouping together of many commercial strains into discrete groups based on their composition.

As study co-author Sarah Stith, an associate professor of economics, explained, “it is important that the inherent heterogeneity in cannabis be measured and leveraged to generate improved and expanded therapeutic benefits rather than lost in an effort to transform cannabis into a conventional medication, e.g., through the FDA’s required standardization of investigational new drugs (IND), which was developed not for an inherently diverse plant species but rather for the mass-produced synthetic chemical compounds that constitute the majority of conventional medications.”

In that vein, the UNM researchers also conducted an additional analysis contrasting the health effects reported after using the five most common chemovar groups identified in the Releaf App data: LM60, M⁺A50, MC61, MC62, and T⁺L60. In these, the researchers were looking for any significant group differences in patient symptom relief for pain, anxiety, and depression-related items.

The researchers confirmed that there were significant group differences in symptom relief between the five chemovar groups studied. Generally, symptom relief was greatest after consumption of the chemovars with slightly higher than average levels of mercene and terpinolene (M+A50 and T+L60) and non-detectable amounts of CBD.

While they only examined a very small sample size of chemovar groups, the researchers say that this proof-of-concept study does support the idea that unique chemovars differ in their therapeutic effects – a long-held observation by cannabis users, but which has been largely untested by the scientific community.

“While the cannabis plant’s natural ability to develop different types of chemical profiles may complicate standardization of cannabis medications, as is typical of conventional pharmaceuticals, its inherent phytochemical heterogeneity may also explain why the Cannabis plant is effective at treating so many different types of health conditions,” said lead researcher Jacob M Vigil, an associate professor in the UNM department of psychology, in a statement.

“I hope that by creating this comprehensive, common-sense, and user-friendly indexing system, scientists, health providers, and most importantly, patients will be better able to identify and distinguish cannabis plant strains and their unique and desired effects, which is the ultimate goal of most cannabis-based research.”