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Scientific Assessment of the JUUL2 System

Nicotine is addictive and can cause certain harms to health. It would be best if no one used any nicotine product. Anyone who smokes should quit. Juul Labs believes that adult smokers who have not successfully quit should completely switch to potentially less harmful alternative nicotine products.

We believe the best method to switch adult smokers from combustible cigarettes is to provide a satisfying alternative with significantly reduced toxicant exposure compared to combustible cigarettes. To accomplish that goal, we are committed to working with governments, regulators, and other key stakeholders in all our markets to create a responsibly regulated and adequately safeguarded vapor category.

The new JUUL2 System — launched Fall 2021 in the United Kingdom — was designed to expand our company’s ability to transition adult smokers, including improving on elements of the product that are important to adult smokers.

As part of our product development process, Juul Labs conducts extensive analyses of the individual ingredients used in our e-liquids, the aerosol created by the device, and potential health hazards.

Our research on the JUUL2 System includes the following:

Nonclinical Research

Our nonclinical research examines JUUL2 System aerosol through analytical chemistry, in vitro studies, and toxicological assessments. This includes:

Testing for Harmful and Potentially Harmful Constituents (HPHCs): Chemical analyses of JUUL2 System aerosol are conducted to quantitatively assess the presence of HPHCs identified by public health bodies such as WHO and the U.S. Food and Drug Administration as key toxicants of concern. We measure the levels of specific constituents in the aerosol and compare them to those found in combustible cigarette smoke.

Our HPHC studies demonstrate significant reductions in measured constituents in JUUL2 System aerosol compared to cigarette smoke.


Cytotoxicity Analysis: In vitro cytotoxicity testing is performed on aerosol condensate to inform toxicological evaluation, including Neutral Red Uptake, per Organisation for Economic Co-Operation and Development guidance (OECD 129).

In in vitro studies, no JUUL2 System aerosol tested caused cytotoxicity (defined as a viability <70% relative to vehicle control), even at doses higher than cigarette smoke. 

Clinical Research

Our clinical research program examines the impact of the JUUL2 System on adult smokers including the rate and level of nicotine absorption in the body, such as:

Pharmacokinetic Studies: Pharmacokinetic studies assess the rate and level of nicotine absorption in the body as well as subjective effects of use of various products. During testing, we analyze regular blood nicotine measurements before, during, and after use of each product to assess nicotine delivery and to help us understand nicotine absorption rates compared to cigarettes and other nicotine-containing products.

*See manuscript for full results.

Our pharmacokinetic research demonstrates a nicotine delivery for a JUUL2 System prototype that is competitive with, but lower, on average, than that of combustible cigarettes.


We will update our publication library with research on the JUUL2 System as we continue to report results from our studies.