Global growth of heated tobacco products: a time series estimate of the number of users, 2014-2024 (Preprint)

BACKGROUND Sales of heated tobacco products (HTP) expanded rapidly after commercial launch in 2014, yet globally comparable estimates of the number of HTP users remain limited. National surveys rarely include standardized HTP measures, and international surveillance platforms do not provide harmonized estimates. A transparent global time series is needed to inform surveillance, modeling, regulation and health policies. OBJECTIVE To construct a reproducible, annual global estimate of HTP users for 2014-2024 using publicly available corporate disclosures, to quantify uncertainty, and to compare the resulting totals with user counts derived from nationally representative survey prevalence data where available. METHODS We compiled annual HTP user counts and heated-tobacco stick shipments from public reports of the main transnational tobacco companies with material HTP activity over 2014-2024. In the primary series, we used company-reported user totals where available and converted shipments to implied users where only volumes were disclosed, with +/-50% sensitivity around brand-specific consumption assumptions. As a secondary, shipments-only sensitivity, we ignored all company user counts and converted all companies’ shipments to users using a literature-based consumption intensity estimates. As a complementary check, we used nationally representative current-use prevalence surveys from 35 countries and converted these to user counts using UN population data and summed across countries. RESULTS Global HTP users increased from negligible levels in 2014 to an estimated 48.9 million in 2024 in the primary disclosure-based series (range 45.6–52.1 million). In the shipments-only sensitivity using literature-based consumption, totals were higher: 67.9 million in 2024 (range 59.7–78.7 million), with a consistent increasing trajectory. Growth was led by PMI throughout the period; BAT gained traction from 2017, and JT contributed smaller but rising shares. The survey-based approach yielded 21.8 million users across 35 countries. Differences across approaches reflect coverage, timing, and counting conventions rather than trend direction. CONCLUSIONS A transparent, updateable global time series indicates rapid HTP uptake from 2014 to 2024. Depending on counting conventions, 2024 totals span 45.6–78.7 million users (primary range 45.6–52.1; shipments-only range 59.7–78.7), with a survey-based lower bound of 21.8 million. As standardized HTP measures enter national surveys, coverage widens, and corporate definitions are clarified, estimates can be recalibrated and uncertainty narrowed.