The addictiveness of nicotine pouches and other oral products may depend on their flavourings, according to a new rat study published in the peer-reviewed journal Nicotine & Tobacco Research.
Nicotine pouches – small sachets placed between the gum and lip, delivering nicotine without tobacco – are surging in popularity. In the US, sales skyrocketed from 126 million units between August and December 2019 to 808 million between January and March 2022.
That growth has only accelerated in the years since. In 2024, Zyn – the best-selling nicotine pouch brand in the US – sold 385 million units by itself, a 50 per cent increase from 2023, according to Forbes.
The new study suggests that certain flavourings and sweeteners can significantly influence nicotine consumption. Using rats, the team tested varying combinations of flavourings and sweeteners combined with nicotine water solution and measured the resulting nicotine intake.
“We wanted to understand how sweeteners and flavours influence nicotine use,” lead author Dr Deniz Bagdas, a research scientist at Yale School of Medicine, told BBC Science Focus. “Many oral nicotine products contain these additives, yet their impact on nicotine choice behaviour and preference is not fully known.”
Previous research by Bagdas and her colleagues had already identified that sweetening nicotine-containing solutions increases consumption. Here, they gave the rats a choice between plain, sweetened, flavoured, or sweetened and flavoured nicotine.
As expected, both male and female rats exhibited a strong preference for the sweetened solutions, but with notable differences: females consumed the most nicotine when it was combined with just sweeteners, while males preferred nicotine when paired with cinnamaldehyde – the principal chemical in cinnamon responsible for its taste and a common flavouring in nicotine pouches.
According to the study’s authors, this shows that flavours may influence male nicotine consumption more than females, who show a greater sensitivity to sweetness. The study also showed that menthol flavouring increased consumption in males but not females, adding weight to this theory.
While the study was conducted in rats, Bagdas noted that rodents and humans share similar reward systems, making the findings relevant to human behaviour (although no similar studies have been just conducted in humans).
“Rodents have well-established taste preferences and reward systems, making them a good model for understanding how additives influence nicotine consumption,” she said.
“They also allow us to isolate and understand the effects of specific sweeteners and flavours on nicotine preference, outside of additional external influences like marketing, social factors or other ingredients found in oral nicotine products.”
With flavoured nicotine pouches widely available and marketed in various forms, the study raises questions about potential regulatory measures.
“By identifying additives that enhance the appeal of oral nicotine products and their potential addiction risk, our findings can inform harm reduction strategies and regulatory policies,” Bagdas said.
“In particular, our work highlights the significant role of sweetness in oral nicotine choice behaviour and intake, suggesting the public health importance of regulating not only flavours but also sweeteners in oral nicotine products.”
Additionally, Bagdas said that more research is needed to investigate other components of oral nicotine products that may influence intake, such as pH modifiers, nicotine source (tobacco-derived vs synthetic) and formulation.
About our expert
Deniz Bagdas, DVM, PhD, is a research scientist in the Department of Psychiatry at Yale School of Medicine, specializing in behavioural neuropharmacology. She serves as a co-investigator at the Yale Center for the Study of Tobacco Product Use and Addiction (Yale TCORS), where she examines the impact of tobacco constituents on nicotine intake, with a particular focus on nicotine addiction behaviours in both adolescents and adults.
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