A Phase 2 interventional study of Cannabidiol - fsCBD and Placebo in Cannabis Use Disorder, sponsored by University of Colorado, Boulder. Recruiting at 1 site in United States. Open to participants aged 21 Years and older. Per ClinicalTrials.gov, last updated 2026-06-12.
Sponsored by University of Colorado, Boulder · Phase 2, Interventional, and Treatment
This study is a placebo-controlled randomized trial comparing the effects of hemp-derived cannabidiol (CBD) with and without Delta-9-tetrahydrocannabinol (THC), relative to placebo, on reducing cannabis use and cannabis use disorder (CUD) symptoms in adult treatment seeking cannabis concentrate users with CUD. Participants enroll in the study for 8 weeks (with telehealth follow-ups at 12 and 16 weeks) and are randomized to either full spectrum CBD, broad spectrum CBD, or placebo. Participants are also engaged in five weeks of psychotherapy treatment for CUD. Blood is collected to quantify investigational drug exposure and cannabis use. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.
As cannabis legalization continues to spread across the United States, average Δ9-tetrahydrocannabinol (THC) concentrations in recreational products have significantly increased, with THC levels as high as 90-95%. The investigators' preliminary data suggest that concentrate use elicits blood THC levels more than twice as high as cannabis flower use, and that concentrate use is associated with greater withdrawal, tolerance, and Cannabis Use Disorder (CUD), prompting concern about the risks of these high potency products in relation to problem use and CUD. No prior study has evaluated effective treatments to reduce cannabis use in this high risk group.
Several previous studies have found that the non-intoxicating cannabinoid cannabidiol (CBD), which may antagonize the effects of THC on CB1 and CB2 receptors, reduces cannabis use and CUD-related symptoms, such as affective disturbance and withdrawal. Results of these studies are promising, but limited to synthetic or isolated forms of CBD that are not widely available. There have been no tests of the hemp-derived CBD that is widely available without a prescription across the U.S. Importantly, hemp-derived CBD comes in two forms, one with a small amount of THC (7.8mg (3.4mg BID) THC, full spectrum; fsCBD) and one without THC (0% THC; broad spectrum; bsCBD). It is possible that a small amount of THC may confer additional benefits with respect to withdrawal and related affective disturbance, and in turn be beneficial for reducing THC use overall. Consistent with this hypothesis, pilot data from the investigators' lab suggest that CBD, that also contains low levels of THC, reduces THC drug reward, withdrawal, anxiety, and overall THC use in heavy concentrate users, supporting the potential for hemp-derived CBD to reduce THC use and mitigate withdrawal in this high risk group. However, no placebo-controlled trial has been conducted comparing hemp-derived CBD with and without THC on reducing THC use.
This study is a placebo-controlled RCT comparing the effects of hemp-derived CBD (fsCBD vs. bsCBD vs. placebo) on reducing THC use in concentrate users with CUD. 150 adult treatment-seeking concentrate users with DSM5 CUD will be recruited to complete an eight-week protocol. Participants will be randomly assigned to take 400 mg of either hemp-derived bsCBD (contains no THC), hemp-derived fsCBD (contains low levels of THC), or matched placebo daily for eight weeks. All participants will receive a five-session empirically supported psychological intervention to support cannabis use reduction during the trial. Participants will be assessed for changes in THC use [self-reported mg of THC used and levels of THC's metabolite 11-nor-9-carboxy-Δ9-THC (THC-COOH)] and CUD symptoms, as well as levels of CBD and CBD's metabolite, 7-Carboxy-Cannabidiol (CBD-COOH) to monitor medication adherence. Primary outcomes include reduction in THC exposure [via self-reported amount used and urine THC-COOH (standardized for creatinine)], CUD symptoms, and withdrawal symptoms, including affective, physiological, and physical symptom facets, across the 8-week study.
University of Colorado, Boulder is the lead sponsor of 88 studies on the registry; 20 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Cannabidiol - fsCBD
Drug: Cannabidiol - bsCBD
Drug: Placebo
Full-spectrum (i.e., fsCBD, 7.8mg THC (3.4mg BID)), plant-derived CBD capsules produced by Ecofibre/Ananda Hemp will be used.
Placebo arm
Broad-spectrum (i.e., bsCBD, 0% THC), plant-derived CBD capsules produced by Ecofibre/Ananda Hemp will be used
Difference in cannabis use
The change in the amount of cannabis used by participants as measured by self-report
Time frame: 8 weeks
Difference in cannabis use
The change in the amount of cannabis used by participants as measured by biomarkers of metabolites
Time frame: 8 weeks
Difference in symptoms of cannabis use disorder (CUD)
The change in symptom levels of CUD as measured by the Cannabis Use Disorders Identification Test (CUDIT). This questionnaire was designed for self administration and is scored by adding each of the 8 items: * Question 1-7 are scored on a 0-4 scale * Question 8 is scored 0, 2 or 4. Scores of 8 or more indicate hazardous cannabis use, while scores of 12 or more indicate a possible cannabis use disorder for which further intervention may be required.
Time frame: 8 weeks
Difference in withdrawal symptoms
The change in three facets of withdrawal including affective, physiological, and physical withdrawal symptoms as measured by the Marijuana Withdrawal Checklist (MWC)
Time frame: 8 weeks
Difference in alcohol use
The change in alcohol use as measured by the Alcohol Use Disorders Identification Test (AUDIT)
Time frame: 8 weeks
Difference in alcohol use
The change in alcohol use as measured by the Timeline Follow-back
Time frame: 8 weeks
Difference in wellbeing and quality of life
The change in wellbeing as measured by the Health Related Quality of Life survey
Time frame: 8 weeks
Difference in emotional states
The change in emotional states as measured by the Depression Anxiety and Stress Scale (DASS). Each of the three DASS-21 scales contains 7 items, divided into subscales with similar content (Depression, Anxiety, and Stress). Scores range from 0-42 for each subscale (0-126 for the total scale), with higher numbers reflecting more negative emotional states over the past week.
Time frame: 8 weeks
Difference in cannabis use
Difference in cannabis use as measured by the DSM-5 Cannabis Use Disorder diagnostic criteria
Time frame: 8 weeks
Moderators of designated outcomes
Exploratory models will examine biological sex and age as a moderators of the designated outcomes
Time frame: 8 weeks
Started Jul 2024 (actual). Primary completion is estimated for Mar 2028, 44 months after the start.
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University of Colorado, Boulder