Nicotine Regulation for Dual Users of E-cigarettes and Cigarettes (RDEC)

June 23, 2025 updated by: Elias Klemperer, University of Vermont

A Randomized Controlled Trial of Reduced Nicotine Cigarettes and E-cigarettes Among Dual Users

Cigarette smoking remains the leading cause of preventable morbidity and mortality in the US. Use of multiple tobacco products is becoming increasingly prevalent, with dual use of e-cigarettes and cigarettes representing the most common combination. Though e-cigarettes are not without risk, completely switching from cigarettes to e-cigarettes likely reduces risk for tobacco-related harm. However, many established dual users maintain long-term smoking and the majority who use e-cigarettes non-daily are at an even greater risk for prolonged smoking than exclusive cigarette smokers. The Food and Drug Administration Center for Tobacco Products (FDA CTP) has announced plans to implement a nicotine-limiting product standard, capping the nicotine in cigarettes at a minimally or non-addictive level. Randomized controlled trials (RCTs) demonstrate that adults who exclusively smoke cigarettes respond to very low nicotine content (VLNC) cigarettes with reductions in smoking, demand, and dependence. However, nicotine reduction RCTs to date have excluded people who regularly use e-cigarettes and therefore it remains unclear how a nicotine-limiting standard for cigarettes would affect smoking among dual users. Given the potential substitutability of e-cigarettes for cigarettes, reducing the nicotine in cigarettes could promote a transition to exclusive e-cigarette use among dual users unable to completely quit nicotine, but only if sufficiently appealing e-cigarettes remain available. E-cigarettes containing 5% nicotine-salt solution are currently most popular in the US, but policy makers have proposed restricting e-cigarettes to ≤ 2% nicotine to curb youth e-cigarette use, and several states have already set limits to reduce nicotine in e-cigarettes. Prior laboratory studies indicate that higher vs lower nicotine e-cigarettes serve as better substitutes for cigarettes among adult dual users. As such, a restriction on e-cigarette nicotine concentration could undermine the potential for e-cigarettes to substitute for cigarettes and diminish the benefits of a nicotine-limiting standard for cigarettes among dual users. This study is a 12-week double-blind 2 cigarette level (Normal Nicotine vs Very Low Nicotine) x 2 e-cigarette level (High Nicotine vs Low Nicotine) between-subjects factorial trial to investigate how a nicotine-limiting standard for cigarettes affects adult dual users and whether these effects are impacted by constraints on e-cigarette nicotine concentration. Outcome measures include cigarettes per day, cigarette dependence, and toxicant exposure. The research is highly relevant to FDA CTP domains of Addiction and Behavior because it will test whether reducing the nicotine content of cigarettes reduces smoking and dependence, and whether these effects are moderated by the availability of high vs low nicotine e-cigarettes.

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.

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.
308

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.
  • Phase 2

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
    • Rhode Island
      • Providence, Rhode Island, United States, 02903
        • Recruiting
        • Brown University
        • Contact:
        • Principal Investigator:
          • Jennifer Tidey, PhD
    • Vermont
      • Burlington, Vermont, United States, 05405

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

Yes

Description

Inclusion Criteria:

  • Regular use of tobacco
  • 21 year of age or older
  • Speak, comprehend and read English well enough to complete study procedures

Exclusion Criteria:

  • Pregnant, trying to become pregnant, or nursing
  • Under the age of 21
  • Health conditions that could undermine ability to complete the study

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: Other
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Triple

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: RC 1 + REC 1
Research cigarettes #1 plus research e-cigarettes #1
Other: Varying the nicotine content of cigarettes
Altering the nicotine content of the tobacco research cigarettes
Other Names:
  • Comparing normal nicotine content (RC 1) to very low nicotine content (RC 2)
Other: Varying the nicotine content of e-cigarettes
Altering the nicotine content of the research e-cigarettes
Other Names:
  • Comparing high nicotine content (REC 1) to low nicotine content (REC 2)
Experimental: RC 1 + REC 2
Research cigarettes #1 plus research e-cigarettes #2
Other: Varying the nicotine content of cigarettes
Altering the nicotine content of the tobacco research cigarettes
Other Names:
  • Comparing normal nicotine content (RC 1) to very low nicotine content (RC 2)
Other: Varying the nicotine content of e-cigarettes
Altering the nicotine content of the research e-cigarettes
Other Names:
  • Comparing high nicotine content (REC 1) to low nicotine content (REC 2)
Experimental: RC 2 + REC 1
Research cigarettes #2 plus research cigarettes #1
Other: Varying the nicotine content of cigarettes
Altering the nicotine content of the tobacco research cigarettes
Other Names:
  • Comparing normal nicotine content (RC 1) to very low nicotine content (RC 2)
Other: Varying the nicotine content of e-cigarettes
Altering the nicotine content of the research e-cigarettes
Other Names:
  • Comparing high nicotine content (REC 1) to low nicotine content (REC 2)
Experimental: RC 2 + REC 2
Research cigarettes #2 + research e-cigarettes #2
Other: Varying the nicotine content of cigarettes
Altering the nicotine content of the tobacco research cigarettes
Other Names:
  • Comparing normal nicotine content (RC 1) to very low nicotine content (RC 2)
Other: Varying the nicotine content of e-cigarettes
Altering the nicotine content of the research e-cigarettes
Other Names:
  • Comparing high nicotine content (REC 1) to low nicotine content (REC 2)

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
Time Frame
Number of cigarettes smoked per day
Time Frame: 12 weeks
12 weeks

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 Vermont

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: Elias Klemperer, PhD, University of Vermont

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.
November 1, 2024

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.
August 31, 2028

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.
September 30, 2028

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).
September 23, 2024

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.
September 23, 2024

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.
September 26, 2024

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.
June 27, 2025

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.
June 23, 2025

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.
September 1, 2024

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.
  • R01DA059562 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be made available once we have published the results of the parent trials and manuscripts based on secondary analyses of those data, which we anticipate taking approximately three years.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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