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ClinicalTrials.gov 27 recruiting now official registry

Smoking clinical trials

27 of 124 indexed Smoking trials are currently recruiting.

124 US clinical trials · 27 currently recruiting

Smoking is the subject of 124 registered US clinical trials on ClinicalTrials.gov, 27 of them currently open to new participants. 13 are in Phase 3-4 (later-stage) and 22 in Phase 1-2 (earlier-stage). The most active sponsor is RAI Services Company, running 9 of these trials.

The research picture

Smoking has 124 registered US clinical trials, 27 of them open to new participants right now, about 22% of the total.

27
recruiting participants now
22%
of trials open to enrollment
13
in Phase 3–4 (later-stage)
9
top sponsor: RAI Services Company
Phase 19Phase 213Phase 34Phase 49

Active & Recent Trials

124 total, page 2 of 3

COMPLETED NA 900 participants

Cessation Service Use and Effectiveness for Hospitalized Smokers

Kaiser Permanente

NCT01236079

COMPLETED NA 864 participants

A Medical Assistant-Based Program to Promote Healthy Behaviors in Primary Care

The University of Texas Health Science Center at San Antonio

NCT00273806

COMPLETED 775 participants

Survey of Smokers Treated in the Emergency Department (ED) on Ownership and Usage of Cell Phones

Yale University

NCT01820533

COMPLETED NA 685 participants

Improving Tobacco Treatment Rates for Cancer Patients Who Smoke

Abramson Cancer Center at Penn Medicine

NCT04738643

COMPLETED NA 672 participants

A 26-week Extension of the ZRHR-ERS-09-US Study Evaluating Biological and Functional Changes in Healthy Smokers After Switching to THS 2.2

Philip Morris Products S.A.

NCT02649556

COMPLETED NA 638 participants

Clinical Outcomes of a Nationwide, Naturalistic E-Cig Trial (CONNECT)

Medical University of South Carolina

NCT03453385

COMPLETED NA 633 participants

Connect to Quit for Smoking

University of Pittsburgh

NCT01299896

COMPLETED 617 participants

Asian Youth and Tobacco Control Survey

M.D. Anderson Cancer Center

NCT00642317

COMPLETED NA 577 participants

Telephone Care Coordination for Smokers in VA Mental Health Clinics

VA Office of Research and Development

NCT00724308

COMPLETED Phase 2 536 participants

Proactive Health Intervention for Tobacco Users (Get PHIT)

Kaiser Permanente

NCT00169260

COMPLETED Phase 2 522 participants

Study of TA-NIC to Assess the Efficacy and Safety of the Vaccine as an Aid to Smoking Cessation

Celtic Pharma Development Services

NCT00633321

COMPLETED Phase 4 517 participants

Identifying Treatments to Motivate Smokers to Quit

University of Wisconsin, Madison

NCT01122238

COMPLETED NA 501 participants

Tobacco Status Project: Social Media Intervention for Young Adult Smokers

University of California, San Francisco

NCT02207036

COMPLETED Phase 4 463 participants

Bupropion SR Plus Counseling for Smoking Cessation

University of Wisconsin, Madison

NCT01621009

COMPLETED NA 400 participants

Improving Health Behaviors Through Telephone Linked Care

American Academy of Family Physicians

NCT00314197

COMPLETED Phase 2 333 participants

Efficacy of Naltrexone in Women's Smoking Cessation

University of Chicago

NCT00271024

COMPLETED 330 participants

HIV-related Accelerated Aging of the Airway Epithelium

Weill Medical College of Cornell University

NCT01974219

COMPLETED NA 300 participants

Strategies to Avoid Returning to Smoking

University of Pittsburgh

NCT00757068

COMPLETED NA 282 participants

Evaluating the Effects of Supplemental Vitamin C on Infant Lung Function in Pregnant Smoking Women

Oregon Health and Science University

NCT00632476

COMPLETED NA 270 participants

Protecting the 'Hood Against Tobacco

University of California, San Francisco

NCT00187603

COMPLETED Phase 3 255 participants

Smoking Cessation for Adults With Attention Deficit Hyperactivity Disorder (ADHD)

University of Cincinnati

NCT00253747

COMPLETED Phase 4 248 participants

Bupropion for Hospitalized Smokers With Acute Cardiovascular Disease

Massachusetts General Hospital

NCT00181818

COMPLETED Phase 1 240 participants

Group Counseling for Smoking Cessation

American University

NCT00104481

COMPLETED Phase 3 232 participants

Tobacco Tactics Website for Operating Engineers

University of Michigan

NCT01124110

COMPLETED NA 210 participants

CSD170304: Study to Assess Nicotine Uptake in Smokers From Electronic and Combustible Cigarettes

RAI Services Company

NCT03294356

COMPLETED NA 196 participants

Innovative Smartphone Application of a New Behavioral Method to Quit Smoking: Pilot Trial (Smart Quit)

Fred Hutchinson Cancer Center

NCT01812070

COMPLETED NA 194 participants

CSD210903: A Study to Determine Subject Puffing Patterns of a Heated Tobacco Product With Four Non-Combusted Cigarette Variants in an Ambulatory Setting

RAI Services Company

NCT05307822

COMPLETED Phase 4 179 participants

Smoking Tobacco and Drinking Study

University of California, San Francisco

NCT03163303

COMPLETED 178 participants

Physiological Responses in Tobacco Chippers

Oregon Health and Science University

NCT01237834

COMPLETED NA 165 participants

A Facebook Intervention for Young Sexual and Gender Minority Smokers

University of California, San Francisco

NCT03259360

COMPLETED Phase 4 120 participants

CPT-SMART for Treatment of PTSD and Cigarette Smoking

VA Office of Research and Development

NCT03978442

COMPLETED 117 participants

Alpha-1 Carrier Genomics Study

Medical University of South Carolina

NCT02810327

COMPLETED NA 117 participants

The Moment Study: Mixed Method E-cigarette Study

Truth Initiative

NCT02261363

COMPLETED Phase 2 114 participants

N-acetylcysteine for Tobacco Use Disorder

Medical University of South Carolina

NCT02737358

COMPLETED NA 114 participants

CSD170501: Study to Assess Biomarkers of Tobacco Exposure in Smokers During In-Clinic Confinement Switch to an Electronic Cigarette

RAI Services Company

NCT03170674

COMPLETED Phase 2 110 participants

Computer-Assisted Intervention for Smoking During Pregnancy

Wayne State University

NCT01028131

COMPLETED Phase 4 101 participants

Long-term Varenicline Treatment for Smoking Cessation

University of Wisconsin, Madison

NCT00828113

COMPLETED NA 100 participants

Electronic Cigarettes (E-cigarettes) as a Harm Reduction Strategy

NYU Langone Health

NCT02628964

COMPLETED Phase 2 100 participants

Modeling Stress-precipitated Smoking Behavior for Medication Development

Yale University

NCT00773357

COMPLETED Early Phase 1 99 participants

Hollings Cancer Center Varenicline Sampling Study

Medical University of South Carolina

NCT03742154

COMPLETED Phase 2 99 participants

Oxidative Stress and Vitamin E Requirements

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NCT00067899

COMPLETED 88 participants

Parent Willingness to Participate in Tobacco Trials in the Pediatric Clinical Setting

St. Jude Children's Research Hospital

NCT01673243

COMPLETED NA 83 participants

A Pilot Randomized Controlled Trial of Financial Incentives, Text Messaging, and Usual Care for Homeless Smokers

Massachusetts General Hospital

NCT02565381

COMPLETED NA 76 participants

Increasing Cessation Motivation and Treatment Engagement Among Smokers in Pain

Syracuse University

NCT03996902

COMPLETED NA 75 participants

CSD200907: A Study to Assess Elements of Abuse Liability for a Heated Tobacco Product With Four Non-Combusted Cigarette Variants

RAI Services Company

NCT05114863

COMPLETED Early Phase 1 64 participants

Impact of Low Nicotine Cigarette Messaging on Perceptions and Cigarette Choices

Masonic Cancer Center, University of Minnesota

NCT04740008

COMPLETED NA 61 participants

Connecting Alaska Native People to Quit Smoking

Mayo Clinic

NCT03645941

COMPLETED NA 59 participants

Smoking Cessation Smartphone App for Cancer Patients (Quit2Heal Study)

Fred Hutchinson Cancer Center

NCT03600038

COMPLETED NA 56 participants

Young Adults' Reactions to Low Nicotine Cigarette Advertising

Abramson Cancer Center at Penn Medicine

NCT04906148

COMPLETED NA 51 participants

Effects of Sulforaphane (SFN) on Immune Response to Live Attenuated Influenza Virus in Smokers and Nonsmokers

University of North Carolina, Chapel Hill

NCT01269723

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Phase Distribution

PhaseTrial count
Phase 1 9
Phase 2 13
Phase 3 4
Phase 4 9

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

Reading the Smoking Trial Landscape

124 indexed Smoking studies · 27 recruiting (22%).

Phase mix: 13 late (III/IV) vs 22 early (I/II).

Top sponsor: RAI Services Company (9 trials), 9 others listed. 50 shown below, recruiting first.

How to read this condition's trial landscape

That ratio is a useful proxy for activity level: a high share of recruiting studies often signals that research interest is current and that new enrollment opportunities are appearing, while a low share typically means the field is dominated by completed or follow-up work where most participant spots have already been filled. These counts reflect the public registry only and include studies at every stage of design, so they should be read as an index of research attention rather than as a measure of treatment availability.

Phase 1 and Phase 2 studies focus on early safety signals, dosing, and preliminary effect, while Phase 3 studies are typically the larger efficacy and safety trials submitted toward regulatory review, and Phase 4 studies follow approved interventions in real-world use. A condition weighted toward later phases often reflects a mature research pipeline with several interventions already close to or past approval, whereas a heavier early-phase tilt suggests the field is still exploring new mechanisms and candidate approaches.

All figures are derived from the public ClinicalTrials.gov dataset maintained by the National Library of Medicine and are reproduced here for reference. Inclusion of a trial, sponsor, or intervention on this page is neither an endorsement nor a recommendation, eligibility, protocol changes, and site-level status can shift frequently, so always verify current details on ClinicalTrials.gov and consult a qualified healthcare provider before acting on anything you see here.

Frequently Asked Questions

How many clinical trials are there for Smoking?

PlainTrial tracks 124 US clinical trials for Smoking, of which 27 are currently recruiting participants. Data sourced from ClinicalTrials.gov.

How do I find a recruiting trial for Smoking?

Use the trial list above filtered by "Recruiting" status, or visit our trial finder at /recruiting to search by condition and state. Always discuss trial participation with your healthcare provider before enrolling.

Is this data current?

Data is sourced from ClinicalTrials.gov and reflects our most recent data pull. Trial status may have changed since then. Always verify current information at ClinicalTrials.gov before making decisions about participation.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from ClinicalTrials.gov (National Library of Medicine). Consult a qualified professional before making decisions based on this data.

Source: ClinicalTrials.gov (NIH/NLM) ClinicalTrials.gov AACT registry · 2026 Trial counts and statuses sourced from ClinicalTrials.gov. Sponsor counts include both industry and federal/academic sponsors.

Verify with NIH →

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This page aggregates every registered trial for this condition, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.