Skip to main content
OpenTrials
Not yet recruiting

NCT Number: NCT07783555

Varenicline as a Treatment for Cannabis Use Disorder

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.

Not yet recruiting

Trial opening soon.

Get Notified

Key information

Conditions

Cannabis Abuse Chemically-Induced Disorders Marijuana Abuse Mental Disorders Substance-Related Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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)
  • Clinically significant cardiovascular or cerebrovascular disease in past 6 months
  • Hypersensitivity to varenicline
  • Participation in another investigational drug study within 30 days

Treatment and study plan

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.

Placebo

Drug

Matched placebo administered daily for 12 weeks.

Primary outcomes

  1. 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.

  2. Group equivalence

    Time frame: Weeks 6-12

    There will equivalence of the average number of weekly use sessions reported between men and women.

  3. 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 .

Study contacts

Contact information is provided by the study sponsor or research team.

Lisa Program Manager, MS

CONTACT

[email protected]

843-792-0476

Sponsors and collaborators

Lead sponsor

Medical University of South Carolina

Other

Collaborators

  • National Institute on Drug Abuse (NIDA)
  • National Institutes of Health (NIH)

Registry information

Important dates

Study start
2026
Primary completion
2031
Study completion
2031
First posted
Aug 25, 2026
Registry last updated
Aug 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.