A Proof-of-Concept Evaluation of the Vigil Index of Cannabis Chemovars: Investigating the Systematic Combinations of Major Cannabinoid and Terpene Contents in Cannabis Flower and Their Effects on Patient Outcomes

A Proof-of-Concept Evaluation of the Vigil Index of Cannabis Chemovars: Investigating the Systematic Combinations of Major Cannabinoid and Terpene Contents in Cannabis Flower and Their Effects on Patient Outcomes.

Cannabis is a plant that has been used for medical purposes for centuries. With the recent legalization of cannabis in many states, there has been an increased interest in understanding the effects of different cannabis strains on patient outcomes. The Vigil Index of Cannabis Chemovars is a novel approach to categorizing cannabis strains based on their major cannabinoid and terpene contents. In this proof-of-concept evaluation, we investigated the systematic combinations of major cannabinoid and terpene contents in cannabis flower and their effects on patient outcomes.

Study Design

The study design was reviewed and deemed exempt from further oversight by the Institutional Review Board at the University of New Mexico due to the retrospective and anonymized nature of the data. The study utilized data from the Releaf App™, MoreBetter, Ltd.’s educational mobile software that enables users to document the labeled characteristics of their cannabis products, cannabis usage characteristics, user health conditions, baseline and momentary symptom intensity levels, and experienced side effects during real-time, in vivo, self-administration sessions.

To be included in the study sample, treatment sessions had to report post-consumption symptom intensity levels at least once within the first hour after session initiation. The final analyzed sample included 204 users who completed 6309 cannabis administration sessions using 633 distinct products with bona fide terpene and cannabinoid content labels between 09/10/2016 and 03/11/2021.

Chemovar Indexing Method

The absolute potency volumes provided on product labels were categorized on ordinal scales, separately for terpene and cannabinoid contents. Distinct plant chemovars were categorized according to a 4-character coding system that broadly describes the relative magnitudes of the primary and secondary terpenes detected and THC and CBD potency levels. The first two characters are the alphabetic symbols for the 20 recorded terpenes, with the highest concentrated terpene in the first place and the terpene with the second-highest concentration in second place.

Within the coding system itself, superscript(s) “+” following an alphabetic symbol indicate one of four possible concentration levels: (no superscript) = 0.01 to 0.49%/dry wt.; “+” = 0.50–0.99%/dry wt.; “++” = 1.00–1.99%/dry wt.; and “+++” = 2.00–3.00%/dry wt. In the main coding system, “-” indicates absence of a second identified terpene; a “/” between terpenes in the first and second places indicate exactly matched concentration levels.

The third and fourth places in the coding system are reserved for absolute THC and CBD potency levels, respectively. The units consist of digits across two separate scales (1–8 for THC, and 0–8 for CBD) representing distribution of most common cannabinoid levels listed on product labels.

Study Outcomes

The study objectives were to identify common examples of unique chemovars and evaluate whether differences exist in their effectiveness at reducing severity of patients’ symptoms, as well as their associations with experienced side effects.

Symptom relief was measured by subtracting (post-dosing) lowest recorded symptom intensity level from baseline (pre-dosing) intensity level resulting in potential symptom changes ranging between -10 (maximum symptom relief) and 9 (minimum symptom relief/maximum increase in symptom severity) points.

The analyses focused on full sample as well as two patient subgroups: (a) consumption sessions used to treat pain (n = 2372, 37.6% of total sample) and (b) consumption sessions for treating either anxiety symptoms or depression (n = 1,062, 16.8%).


ANCOVAs were used to measure relationships between exemplified chemovars and symptom relief within first hour following consumption as well as between chemovars and experienced side effects reported during that first hour.

The study found that there were significant differences in symptom relief among different chemovars when controlling for baseline symptom intensity level and total terpene contents as covariates. Additionally, there were significant differences in experienced side effects among different chemovars when controlling for total number of side effects recorded as covariate.


One limitation of this study is its retrospective nature utilizing data collected through an app-based self-reporting process with potential inaccuracies due to user reporting error or omission. Another limitation is potential lack of generalizability due to use limited to products available within legal states’ markets or through illicit channels.


The findings suggest that there are significant differences in patient outcomes associated with variations in major cannabinoids and terpene contents in cannabis flower. This proof-of-concept evaluation contributes to a growing body of evidence for the efficacy of plant chemovar categorization methods, and provides support for further research into the ways in which chemovars can guide individualized treatment regimens and optimize patient outcomes.

Dr. Paul Miller, MD

Dr. Miller is committed to finding new and innovative ways to help his patients manage their symptoms and improve their overall quality of life. He has a particular interest in the therapeutic potential of medical cannabis and is passionate about educating both his colleagues and patients on its safe and effective use. He is also committed to continuing his education and staying up-to-date on the latest advances in neurology and cannabis research.

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