glo clinical study


We have published the 6-month results from our clinical study on our Tobacco Heating Product, glo.

This important study shows that completely switching to glo has a similar impact on indicators of potential harm as quitting smoking.

Watch the video to see how our clinical study was designed and what the results mean.

glo clinical study

6-month results published

Our research has been published in the journal Internal and Emergency Medicine, and it provides the first real-world evidence that people switching from cigarettes to exclusive use of glo, our flagship THP, can significantly reduce their exposure to certain toxicants and indicators of potential harm related to several smoking-related diseases compared with continuing to smoke.

The results, recorded at 6-months of a 12-month study, showed that switching completely to glo resulted in statistically significant changes across a range of “biomarkers of exposure” (BoE)**, and indicators of potential harm, known as “biomarkers of potential harm” (BoPH)**, compared with continuing to smoke.

For most biomarkers measured, the reductions seen in people using glo were similar to those in participants who stopped smoking completely.

Based on the toxicants measured, glo users showed a:

  • Significant reduction in a biomarker for lung cancer risk
  • Significant reduction in white blood cell count, an inflammatory marker indicative of cardiovascular disease risk (CVD) and other smoking-related diseases
  • Improvement in HDL cholesterol associated with reduced risk of CVD
  • Improvements in two key indicators of lung health
  • Improvement in a key indicator of oxidative stress, a process implicated in several smoking-related diseases, such as CVD and hypertension

Watch the video below to dive into the data

glo study

About the study

Participants in this year-long randomised controlled study were UK-based smokers aged 23 to 55 in good general health who either did or did not want to quit. The smokers who did not intend to quit were randomised to either continue smoking cigarettes or switched to using only glo, while smokers who indicated they wanted to quit smoking received nicotine replacement therapy and access to a cessation counsellor. A group of “never smokers” was also included to act as a control group and continued not to use any tobacco or nicotine products.

This study was designed to explore the risk reduction potential of glo when used in a real world setting rather than in a controlled setting. The only intervention was a monthly clinic visit where samples of blood, urine and other measurements were taken. These samples were tested for “biomarkers of exposure” (to selected cigarette smoke toxicants) and “biomarkers of potential harm”. In addition, to ensure compliance, the glo and cessation groups were tested for the biomarker, CEVal, which indicated if they had recently smoked cigarettes.

Further results from the completed study are due by the end of 2021 and will determine whether the reduced exposure to toxicants and biomarkers of potential harm are maintained over the duration of the study.

In the video below, our Chief Medical Officer talks about the importance of sharing robust data.

Chief medical officer

* Based on the weight of evidence and assuming a complete switch from cigarette smoking. These products are not risk free and are addictive.


Biomarker of Exposure Associated toxicant Carcinogen Respiratory Toxicant CV Toxicant Reproductive Toxicant
NNN NNN Y      
1-OHP Pyrene Y      
NNAL NNK Y      
o-Tol o-toluidine Y      
3-HPMA Acrolein   Y Y  
HMPMA Crotonaldehyde Y      
4-ABP 4-aminobiphenyl Y      
eCO Carbon monoxide       Y
HEMA Ethylene oxide Y Y   Y
2-AN 2-aminonaphthalene Y      
MHBMA 1,3-butadiene Y Y   Y
S-PMA Benzene Y   Y Y
CEMA Acrylonitrile Y Y    


Biomarker of Potential Harm Indicator Association
HDL Lipid metabolism CVD
WBC General inflammation CVD, COPD, cancers
FEV1 Lung health Respiratory disease
FeNO Bronchodilation/vascular tone Respiratory disease, CVD
sICAM Endothelial dysfunction CVD
11-dTx B2 Platelet activation/coagulation CVD
8-epi-PGF2a Oxidative stress CVD, COPD, cancers
NNAL NNK exposure Lung cancer