Testing Warning Labels for Retail Cannabis Products Using a Discrete Choice Experiment

July 24, 2026 updated by: University of Oklahoma

Developing and Testing Warning Labels for Retail Cannabis Products

This discrete choice experiment (DCE) study aims to address gaps in cannabis packaging regulatory research by testing how variations in cannabis packaging and health warning design impact reactions to packaging and intentions about cannabis use. The goal of this work is to identify the most effective combination of health warning features to improve consumer awareness of cannabis health risks. Establishing criteria for cannabis products in the US is critical because inconsistent state guidelines have resulted in contradictory policies in legal retail states, arguably leading to increased hazardous use and failure to meet public health standards. The contributions of this study's outcomes are expected to be significant because they will benefit public health as cannabis becomes available in legal retail markets and regulatory and governmental agencies seek effective ways to communicate cannabis risks to the public.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The DCE will be conducted via a self-administered online questionnaire, with inclusion criteria assessed before assignment to choice set conditions. Participants will be residents of legal-retail cannabis use states, able to legally purchase cannabis (21 or older), who have used cannabis in the past 30 days (i.e., current use). Frequency of cannabis use (i.e., monthly, weekly, daily), mode (e.g., flower, vape, etc.), and dose (i.e., THC level) will be measured through self-report. Inclusion criteria are reported using cannabis (any mode) in the past 30 days. Consented participants will be presented with descriptions of cannabis packaging attributes and an example choice set to become familiar with DCE tasks. Participants will be asked to imagine the cannabis products in the DCE as the only choices they have available to them "in the near future" and to evaluate images within this scenario. Participants will be randomly assigned to view 16 choice sets. To optimize the evaluation of preferences and reduce respondent burden, we will assign contrasting labels to "choice sets," each of which will include 4 images of products in such a way that each attribute level appears an equal number of times in combination with all other attribute levels. Presentation order of the 16 choice sets will be randomized within and across choice sets to minimize ordering effects. Participants will view each choice set for as long as they wish. After evaluating choice sets, participants will complete a recall task to assess retention of health warning information and will be provided a debrief page with information about substance use and resources for seeking help with substance use.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
450

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73104
        • Recruiting
        • University of Oklahoma
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Study Population

The study population consists of adults aged 21 years and older residing in U.S. states with legal retail cannabis markets (i.e., adult use non-medical or "recreational") who report cannabis use within the past 30 days. Participants will be recruited from an online consumer research panel and will represent active adult cannabis consumers in these jurisdictions.

Description

Eligibility for participation includes: 1) being 21 years of age or older, 2) being able to speak and understand English, 3) self-reported having consumed cannabis in the last 30 days (any mode, e.g., flower, vape, edible, etc.), and 4) residing in a U.S. state or jurisdiction where retail (i.e., non-medical) cannabis use is legal.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Discrete choice experiment (DCE) cohort
Adult participants (21+) enrolled in this single-arm cohort will complete a computer-based discrete choice experiment during a single study visit (conducted online). They will review a series of hypothetical cannabis products and select their preferred options.
Behavioral: Discrete choice experiment (DCE) survey-experiment
A discrete choice experiment (DCE) consisting of 16 distinct choice sets. Each choice set presents combinations of the following attributes: 1) Cannabis package style: 1) "Standardized" plain package, 2) plain package with brand logo and fonts, 3) brand color background with brand logo and fonts, and 4) fully branded with brand imagery, brand logo, and brand descriptors and fonts. Branding type: 1) Adventure brand vs. 2) Earthy brand. Health warning size: 1) Small (20% of packaging surface) - health warnings use currently mandated warning language from multiple jurisdictions vs. 2) Large (40% of packaging surface) - health warnings use currently mandated warning language from multiple jurisdictions. Product THC content: 1) Low THC vs. 2) High THC. Product type: 1) Joints, 2) Vape, 3) Edibles, and 4) Drinks. Participants will rate all combinations of product attributes.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Risk perceptions about cannabis products
Time Frame: At the time of survey completion (approximately 15 minutes)
Binary measure using best-worst scaling. For each question, participants will also have the option of indicating none of the above/opt-out as a response. For each choice set, the statement selected as the best option will be coded using a value of 1, and the worst will be coded as -1. The remaining statements in that set will be coded as 0. If the participant selects none of the above, all statements in that choice set will be assigned a value of 0.
At the time of survey completion (approximately 15 minutes)
Cannabis product use intentions
Time Frame: At the time of survey completion (approximately 15 minutes)
Binary measure using best-worst scaling. For each question, participants will also have the option of indicating none of the above/opt-out as a response. For each choice set, the statement selected as the best option will be coded using a value of 1, and the worst will be coded as -1. The remaining statements in that set will be coded as 0. If the participant selects none of the above, all statements in that choice set will be assigned a value of 0.
At the time of survey completion (approximately 15 minutes)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Oklahoma

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute on Drug Abuse (NIDA)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Zachary Massey, PhD, University of Oklahoma

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 19, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 7, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 14, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 17276
  • 1K01DA057395-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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