NCT05338801 · Florida International University
Effect of Menthol on ENDS Users' Addiction and Exposure
What this study is about
The use of electronic nicotine delivery systems (ENDS; e-cigarettes) has reached epidemic levels among young people in the United States (US). ENDS heat and vaporize a nicotine-containing liquid to produce an inhalable aerosol mist.
View original scientific description
The use of electronic nicotine delivery systems (ENDS; e-cigarettes) has reached epidemic levels among young people in the United States (US). ENDS heat and vaporize a nicotine-containing liquid to produce an inhalable aerosol mist. While generally considered less harmful than combustible cigarettes, ENDS use exposes users to dependence-producing nicotine and respiratory and cardiovascular toxicants such as aldehydes. Flavor is a major factor in getting young people to use ENDS, thus limiting flavors to menthol and tobacco for prefilled cartridge ENDS "pod mods" was the first major action taken by the FDA to reduce the spread of ENDS among young people. Menthol flavor, however, can present a potential risk given its increasing popularity among young people in the US, and its puffing and nicotine-enhancing properties. Yet, the extent of menthol's ability to affect users' experience and puffing patterns, and how these affect dependence, exposure to toxicants, and clinical outcomes continue to be understudied. Such evidence will be critical to the FDA's ability to set further regulatory standards to reduce ENDS potential harm. The investigators will conduct a 2x2 (pre-post x menthol vs. tobacco flavor) crossover clinical lab study. The investigator will recruit current/past month ENDS users (n=250, 21-35 yrs), who will attend two sessions and use their ENDS once with menthol and once with tobacco flavors. The proposed studies will answer two key regulatory questions consistent with FDA's focus on the role of flavor in tobacco products' addiction and toxicity; 1) compared to tobacco flavor, does menthol carry additional risk by enhancing puffing, abuse liability, and toxicant exposure in ENDS users, and; 2) is this effect more pronounced among high dependence compared to other users. Other outcomes such as harm perception, satisfaction, clinical responses, intention to use or quit, and group comparisons such as according to race, and sex will allow the FDA a comprehensive assessment of the pros and cons of regulating mentholated ENDS for different segments of the society. Such evidence will help advance FDA regulatory policies with the potential to reduce ENDS harm.
Interventions
OTHER
Menthol-flavored e-cigarette
All participants will complete a lab visit where they will use menthol-flavored e-cigarette ad libitum for up to 60 minutes.
OTHER
Tobacco-flavored e-cigarette
All participants will complete a lab visit where they will use tobacco-flavored e-cigarette ad libitum for up to 60 minutes.
Primary outcome measures
Plasma nicotine
Time frame: During the 2 participant visits. Blood will be taken 2 times in each e-cigarette use session: before and after an approximately 60 minutes ad lib use period
Change in plasma nicotine level
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Generally healthy individuals (determined by physical examination).
- Age of 21-35 years.
- Is willing to provide informed consent.
- Is willing to attend the lab as required by the study protocol.
- E-cigarette users (defined as using e-cigarette either daily or occasionally in the past 30 days)
- Have abstained from e-cigarette use for 12 hours prior to each session
Exclusion criteria
- Report smoking cigarettes regularly (\> 5 cigarettes/month in the past year).
- Report regular use of any other tobacco/nicotine product (e.g., e-cig, pipes, cigars) in the past year.
- Women who are breast-feeding or test positive for pregnancy (by urinalysis at screening).
- Individuals with self-reported history of chronic disease or psychiatric conditions.
- Individuals with history of or active cardiovascular disease, low or high blood pressure, seizures, and regular use of prescription medications (other than vitamins or birth control).
- Individuals that report current THC (marijuana) smoking/vaping.
- Individuals that report current EVALI or COVID-19 related symptoms (i.e., cough, shortness of breath, chest pain, nausea, vomiting, abdominal pain, diarrhea, fever, chills, or weight loss)
- Individuals that have or have been exposed to COVID-19 in the last 14 days.
Where
- Miami, Florida
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 1, 2026 · Source of record for eligibility and locations