PROJECT SUMMARY
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. Our team of
experts in tobacco regulatory science will apply clinical and analytical laboratory methods to address this gap
in evidence by conducting a 2x2 (pre-post x menthol vs. tobacco flavor) crossover clinical lab study. We will
recruit current/past month ENDS users (n=200, 21-35 yrs), who will come to the lab for two sessions and use
their ENDS once with menthol and once with tobacco flavors. While we apply standard and well-tested lab
models suitable for regulatory-related research, we have supplemented these with cutting-edge puffing robot
technology to detect ENDS-associated emissions of toxicants. 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.