Cannabis AbusePhase 2NCT07783555
Varenicline as a Treatment for Cannabis Use Disorder
A Phase 2 study testing Varenicline (Chantix) in people with Cannabis Abuse, run by Medical University of South Carolina.
Trial summary
Marijuana is the most commonly used illicit drug, and there is a high demand for effective treatments for cannabis use disorder, yet few specific pharmacological treatments have been developed. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cannabis Abuse
- What is being tested?
- Varenicline (Chantix)
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 224 participants
- Where
- No sites listed yet
- Study dates
- 1 Dec 2026to 30 Nov 2031
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- DSM-5 diagnosis of cannabis use disorder
- Cannabis use ≥ 3 days per week in past 30 days
- Ability to read English and provide informed consent
- Willingness to comply with medication and study procedures
- Agreement to use acceptable contraception if of childbearing potential
Who cannot join
- Pregnant, breastfeeding, or planning pregnancy
- Severe renal impairment (CrCl < 30 mL/min)
- Lifetime bipolar I or II disorder, schizophrenia, or other psychotic disorder
- Suicidal ideation or behavior within 6 months
- Use of excluded psychotropic medications (e.g., bupropion, nortriptyline)
- Moderate or severe non-cannabis substance use disorder (except nicotine)
Show all 9Show fewer
- Clinically significant cardiovascular or cerebrovascular disease in past 6 months
- Hypersensitivity to varenicline
- Participation in another investigational drug study within 30 days
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Marijuana is the most commonly used illicit drug, and there is a high demand for effective treatments for cannabis use disorder, yet few specific pharmacological treatments have been developed. This study will evaluate the efficacy and safety of varenicline for reducing marijuana use in adults who use marijuana frequently. Participants will be randomized to receive either varenicline or placebo for 12 weeks, along with computerized cognitive behavioral therapy. Cannabis use, medication adherence, and safety outcomes will be assessed throughout treatment and at a follow-up visit.
- Conditions
- Cannabis Abuse
- Being tested
- Varenicline (Chantix), Placebo
- Medical subject headings
- Marijuana Abuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Varenicline (Chantix)Drug
Varenicline will be provided at the standard recommended dose of 0.5mg daily for three days, then 0.5mg twice daily for four days, and then 1mg twice daily for the remainder of the 12-week treatment period.
PlaceboDrug
Matched placebo administered daily for 12 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Varenicline | Active comparator | Varenicline will be provided at the standard recommended dose of 0.5mg daily for three days, then 0.5mg twice daily for four days, and then 1mg twice daily for the remainder of the 12-week treatment period. Receives: Drug: Varenicline (Chantix) |
| Placebo | Placebo comparator | Matched placebo administered daily for 12 weeks. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cannabis use reduction
The primary efficacy outcome is cannabis use reduction as measured by daily substance use logs and examined as the total number of use sessions at each weekly visit.
Measured: Weeks 6-12
Group equivalence
There will equivalence of the average number of weekly use sessions reported between men and women.
Measured: Weeks 6-12
Treatment responder classification
Determine what baseline demographic, cannabis use, and clinical characteristics best differentiate positive study treatment responders as compared to non-responders .
Measured: Weeks 6-12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Aug 2026
- Study start1 Dec 2026 (estimated)
- Primary completion30 Nov 2031 (estimated)
- Study completion30 Nov 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cannabis AbuseStudies of the same condition, open and under way.
- More trials run by Medical University of South CarolinaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 224 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of South Carolina
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH)
- Responsible party
- Principal investigator, Aimee McRae-Clark, Medical University of South Carolina
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07783555
- Sponsor's protocol ID
- Pro00150924
- Status last verified
- Aug 2026
- First submitted
- 20 Aug 2026
- Last updated
- 25 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Varenicline as a Treatment for Cannabis Use Disorder
- ClinicalTrials.gov ID
- NCT07783555
- Acronym / sponsor ID
- Pro00150924
- Conditions
- Cannabis Abuse
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 224 participants (estimated)
- Lead sponsor
- Medical University of South CarolinaUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH)
- Study start
- 1 Dec 2026 (estimated)
- Primary completion
- 30 Nov 2031 (estimated)
- Study completion
- 30 Nov 2031 (estimated)
- First posted
- 25 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Marijuana is the most commonly used illicit drug, and there is a high demand for effective treatments for cannabis use disorder, yet few specific pharmacological treatments have been developed. This study will evaluate the efficacy and safety of varenicline for reducing marijuana use in adults who use marijuana frequently. Participants will be randomized to receive either varenicline or placebo for 12 weeks, along with computerized cognitive behavioral therapy. Cannabis use, medication adherence, and safety outcomes will be assessed throughout treatment and at a follow-up visit.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Varenicline | Active comparator | Drug: Varenicline (Chantix)Varenicline will be provided at the standard recommended dose of 0.5mg daily for three days, then 0.5mg twice daily for four days, and then 1mg twice daily for the remainder of the 12-week treatment period. |
| Placebo | Placebo comparator | Drug: PlaceboMatched placebo administered daily for 12 weeks. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥ 18 years
- DSM-5 diagnosis of cannabis use disorder
- Cannabis use ≥ 3 days per week in past 30 days
- Ability to read English and provide informed consent
- Willingness to comply with medication and study procedures
Key exclusion criteria (9 listed)
- Pregnant, breastfeeding, or planning pregnancy
- Severe renal impairment (CrCl < 30 mL/min)
- Lifetime bipolar I or II disorder, schizophrenia, or other psychotic disorder
- Suicidal ideation or behavior within 6 months
- Use of excluded psychotropic medications (e.g., bupropion, nortriptyline)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Varenicline (Chantix)Varenicline will be provided at the standard recommended dose of 0.5mg daily for three days, then 0.5mg twice daily for four days, and then 1mg twice daily for the remainder of the 12-week treatment period. | Drug | Varenicline |
| PlaceboMatched placebo administered daily for 12 weeks. | Drug | Placebo |
Primary outcome
Cannabis use reduction
Time frame: Weeks 6-12
The primary efficacy outcome is cannabis use reduction as measured by daily substance use logs and examined as the total number of use sessions at each weekly visit.
Group equivalence
Time frame: Weeks 6-12
There will equivalence of the average number of weekly use sessions reported between men and women.
Treatment responder classification
Time frame: Weeks 6-12
Determine what baseline demographic, cannabis use, and clinical characteristics best differentiate positive study treatment responders as compared to non-responders .
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Varenicline (Chantix) in people with Cannabis Abuse, run by Medical University of South Carolina.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lisa Program Manager, MS (843-792-0476, jenkinli@musc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cannabis use reduction (time frame: Weeks 6-12). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.