An interventional study of commercially available cannabis administered prior to commercially available alcohol and commercially available alcohol administered prior to commercially available cannabis in Alcohol Use Disorder and Cannabis Use, sponsored by University of Colorado, Denver. Completed at 1 site in United States. Open to participants aged 21 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-18.
Sponsored by University of Colorado, Denver · Not applicable, Interventional, and Other
The goal of this study is to learn about the effects of combining alcohol with cannabis concentrate products which contain high levels of THC. The main question[s] it aims to answer are, 1) How does the order in which someone consumes THC and alcohol in a given co-use session impact outcomes such as blood alcohol level, heart rate or subjective drug effects, and 2) how does THC percentage in cannabis influence outcomes following alcohol and cannabis co-administration. Participants will be scheduled for our mobile lab to come to their residence. During the session, they will:
Researchers will compare people who use alcohol prior to cannabis to those who use cannabis prior to alcohol to determine whether order of use impacts outcomes.
Individuals who drink alcohol commonly report co-using cannabis, and the increasing availability of new formulations of highly potent cannabis products on the legal market means that alcohol is likely being combined with cannabis products that contain high levels of delta-9-tetrahydrocannabinol (THC). There is limited existing research on the acute effects of cannabis products containing high amounts of THC, such as cannabis concentrates, which often contain up to 90% THC. Existing laboratory data suggests that consuming alcohol and cannabis together (compared to alcohol alone) is associated with reduced BAC, delayed time to peak blood alcohol concentration (BAC), longer duration of intoxication, and increased subjective intoxication, but it is unknown how cannabis concentrates may interact with alcohol to influence these outcomes. There is also a lack of research regarding whether timing or order of use matters, though recent survey data from our group and others suggests that using alcohol before cannabis may confer additional risk compared to using cannabis prior to alcohol. The present study leverages a federally-compliant mobile laboratory design to explore the acute effects of self-administered cannabis concentrates alongside a standardized dose of alcohol. The investigators will recruit a community sample of individuals who regularly use alcohol and cannabis to participate study sessions in our mobile laboratory. The sessions will involve individuals consuming cannabis concentrates of their choice (that they acquire themselves) along with a standardized dose of alcohol. Half of the participants will use the alcohol before cannabis, and the other half will use the cannabis before alcohol. The investigators will measure intoxication and biological outcomes every 30 minutes for 4 hours. The investigators will also measure differences between those who used alcohol before cannabis and those who used cannabis before alcohol.
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Exclusion Criteria:
Participants are randomly assigned to receive the standardized alcohol dose during the experimental session prior to going inside their residence to self-administer their preferred cannabis concentrate product.
Other: commercially available alcohol administered prior to commercially available cannabis
Participants are randomly assigned to go inside their residence to self-administer their preferred cannabis concentrate product and then receive the standardized alcohol dose.
Other: commercially available cannabis administered prior to commercially available alcohol
Self administration of cannabis prior to researcher administered alcohol
Researcher administered alcohol prior to self-administration of cannabis
Breath Alcohol Level (BrAC)
Breath alcohol level will be measured using a breathalyzer repeatedly during the experimental session
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
Alcohol Urge Questionnaire (AUQ)
The AUQ is a self-report measure of urge for alcohol and has been validated for real-time assessment of alcohol craving in the laboratory. The total score on the measure ranges from 0-48 where higher is worse
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
Heart Rate (HR)
Heart rate (beats per minute) is measured using a finger pulse oximeter
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
ARCI Marijuana Scale
The ARCI scale measures subjective responses to cannabis. total score ranges from 0-12 where higher is worse
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
DRUID Psychomotor Battery
The DRUID is a mobile app that tests for cognitive and motor impairment, and has been shown to detect impairment related to alcohol and cannabis use. total score ranges from 0-100 where higher is worse.
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
Blood-THC
We will quantify levels of THC in the blood before and after the participant uses their cannabis product
Time frame: Blood is drawn immediately prior to alcohol and cannabis consumption, again 60 minutes post alcohol administration start time, and again 240 minutes post alcohol start time
Biphasic Effects of Alcohol Scale (BAES)
The BAES measures the stimulating and sedating effects of alcohol and is validated for use in laboratory settings. This scale produces a stimulation subscale (total score ranges from 0-70 where higher is more stimulated) and a sedation subscale (total score ranging from 0-70 where higher is more sedated)
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
Profile of Mood States (POMS)
The POMS is a self-report rating scale that assesses state-level, distinct mood states. The POMS produces multiple subscales (Tension, depression, anger, fatigue, confusion, vigour, as well as a total mood disturbance scale)
Time frame: Baseline (pre ingestion) and every 30 minutes (post ingestion) for a total of 270 minutes (9 measures)
Plan to share: No
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University of Colorado, Denver