Appeal and Sensory Characteristics of Oral Nicotine Products in Young Adults Who Vape E-Cigarettes

Abstract

Introduction

This study applied a novel tobacco regulatory science paradigm to characterize inter-product variation in the appeal and sensory features of emerging commercial and therapeutic oral nicotine products (ONPs) among young adults who vape e-cigarettes.

Aims and Methods

Twenty-three young adults without ONP experience who use e-cigarettes completed a single-blind, single-visit remote lab study. Participants rated appeal and sensory characteristics during 5-minute standardized self-administrations of eight ONPs (four fruits and four mints) from various brands (Lucy, Rouge, Solace, Nicorette, On!, and Velo). Participants were randomized between-subjects to ONP type (pouches or gum).

Results

Gum ONPs were rated sweeter (B = 19.5, 95% Confidence Interval (CI) = 4.3, 34.7), stronger in flavor (B = 25.6, 95% CI = 12.2, 39.0), and lower in tingling sensation (B = −14.0, 95% CI = −27.8, −0.2) than pouches. Fruit-flavored ONPs were sweeter (B = 12.9, 95% CI = 6.1, 19.7) and caused less burning (B = −12.0, 95% CI = −19.5, −4.5) than mint. Product type × flavor interactions found that gum versus pouch enhanced sweetness and flavor strength more for fruit than mint, while pouch versus gum increased burning and harshness more for mint. Nicorette White Ice was most appealing, while Rogue Fruit and Nicorette Mint were less so. Appeal correlated with most types of sensory experiences (rs = −0.33–0.54), except for tingling and burning.

Conclusions

Nicotine gums may offer a more pleasant sensory experience than pouches for young adults who use e-cigarettes, with variation across brand/flavor variants.

Implications

Results indicate that gum ONPs and fruit flavors may offer greater appeal and a more pleasant sensory experience than pouch ONPs and mint flavors for young adults who use e-cigarettes and are ONP-naïve, with heterogeneity in user experience across some brand/flavor variants. This study also introduces a method for assessing the appeal and sensory features of ONPs, which can inform regulatory efforts and strategies to reduce nicotine dependence among young adults who use e-cigarettes.

Introduction

Young adults have high rates of tobacco use,¹ with 17.2% of young adults reporting past-month vaping in 2022.² This is a cause for concern given the risk for nicotine addiction and poly-substance use.^3,4 Recently, flavored commercial oral nicotine products (ONPs), including pouches and gums, have seen substantial growth in sales⁵ and extensive marketing campaigns conducted.^6–9 These commercial ONPs may be particularly attractive to young adults who use e-cigarettes and may use these products for nicotine satiation at times when vaping is not possible, thereby sustaining nicotine addiction^10,11 and increasing oral health issues.¹² Recent work has indicated that some young adults, particularly those who do not use nicotine and might have otherwise refrained from tobacco use, may be susceptible to ONP use,¹⁰ while others may find ONPs to be a harm reduction or a quit aid.¹⁰ It is important to note that emerging commercial ONPs differ from ONPs that are FDA-approved smoking cessation aids, specifically in terms of regulation. Emerging commercial ONPs are regulated as tobacco products in the United States and are not approved by the FDA as medications for smoking cessation or any other purpose. Considering potential impacts on public health, it is imperative that empirical research assesses the appeal of ONPs among young adults.

Newer commercial ONPs differ from other commercial oral tobacco products (eg, snus, chewing tobacco, etc.) in ways that could influence their appeal among young adults who vape. Emerging commercial ONPs may be used in settings where e-cigarettes or other tobacco products cannot be used (eg, public establishments, college campuses, and workplaces). In addition, because newer ONPs typically do not require spitting, unlike smokeless oral tobacco, discreet use is possible.¹³ Industry-funded research shows that nicotine liberation from nicotine pouches (56%–59%) exceeded that of snus or smokeless tobacco (19%–33%)¹⁴ and blood nicotine delivery from 6 mg nicotine pouch exceeds 8 mg nicotine snus.¹⁴ Thus, ONPs have the ability to adequately deliver nicotine when other nicotine/tobacco products cannot be used.¹⁴ Given these factors and that poly-tobacco use is common among young adults,¹⁵ dual use of commercial ONPs could perpetuate nicotine dependence when combined with e-cigarette use.^15,16

Similar to e-cigarettes,^17–22 the presence of fruit and mint flavorings in commercial ONPs could impact appeal by altering sensory experiences, potentially increasing enjoyment, and resulting in greater use.²³ Additionally, U.S. Food and Drug Administration (FDA)-approved smoking cessation gums (ie, therapeutic ONPs, also known as a nicotine replacement therapy) are now sold in unique fruity and minty flavors (eg, Nicorette’s Fruit Chill²⁴), which may increase their appeal even in the context of previous research showing negligible abuse liability of flavored smoking cessation gum products.²⁵ The familiarity of these flavors in ONPs may attract young adults to use ONPs alongside e-cigarettes.²⁶ Moreover, the cooling agents in mint and menthol flavors, including synthetic cooling agents (eg, WS-3 and WS-23), may mitigate the harshness of nicotine, making higher dosages tolerable to consume.^6,27,28 While attributes like sweetness and coolness are known to influence e-cigarette use in young populations,²³ it is essential to examine which sensory attributes and flavors young adults find most appealing in ONPs. This information will allow us to identify actionable product characteristics that can be regulated to limit the uptake of ONPs by young people.

Variations across ONP types (gum vs. pouch) and brands may also give rise to different user experiences that impact their appeal to young adults. While evidence suggests that adolescents and young adults who are shown ONP packaging images perceive commercial gums as more appealing than pouches,^16,28 it is unknown whether such differences would be observed when actually using the products. Furthermore, it is plausible that young adults may prefer particular brands or brand-flavor combinations of ONPs because of variance in constituents within and across brands.^29,30 Previous trends observed specific e-cigarette brands and brand-flavor combinations (eg, JUUL mint) that became widely used among young people.^31–35

Many commercial ONPs have pending premarket tobacco product applications (PMTA) and are currently being sold in the United States without authorization,³⁶ suggesting further research on ONP appeal could inform regulatory actions on pending ONP PMTAs. Human laboratory paradigms can test the effects of specific product characteristics on appeal under blind conditions capable of controlling for exogenous factors, such as packaging, brand, and flavor name.²⁵ While a standardized appeal and sensory rating procedure have proven to be effective for testing various e-cigarette product characteristics,^{17–19,21,22,37} it is important to investigate whether this method can also be used to examine the appeal and sensory effects of recently marketed commercial ONPs and FDA-approved smoking cessation ONPs. Thus, we adapted and integrated methodologies from consumer product testing evaluation^18,19,21,37 used previously with e-cigarettes to explore the feasibility of employing similar approaches in the assessment of ONPs.

This laboratory experiment examined ONP product appeal and sensory attributes in young adults who use e-cigarettes, and report having interest in, but limited prior experience using commercial ONPs. The first aim was to assess the effects of flavorings and ONP product type (ie, gum vs. nicotine pouch) on appeal and sensory ratings of 14 recently marketed commercial (non-therapeutic) pouch and gum ONPs and two new FDA-approved smoking cessation ONPs. The secondary aim was to explore appeal ratings across the different 16 products and brands. The third aim was to investigate the correlation between sensory attributes and appeal ratings to elucidate which sensory characteristics might be most important to ONP appeal.

Methods

Participants

Young adults (N = 23) who use e-cigarettes (N = 17) and/or dually use e-cigarettes and cigarettes (N = 6) were recruited via nationally distributed online advertisements and participated in the remote study from May to July 2022. Eligibility criteria were: (1) aged 21–29 years, (2) any past 30-day e-cigarette use,³⁸ (3) access to a location where study sessions can be conducted without interruption (eg, residence), (4) access to an electronic device (eg, laptop, tablet, and smartphone) and consistent Internet connection to conduct online study sessions via Zoom, and (5) willingness to try ONPs. Exclusion criteria were: (1) having the plan to reduce or quit vaping, (2) current use of smoking cessation medication (eg, Nicotine Replacement Therapy), (3) use of an ONP in the last 30 days (to avoid effects of recent exposure to the ONP study product class), (4) daily use of other nicotine products (ie, non-e-cigarette or tobacco products), (5) being pregnant or breastfeeding, and (6) medical conditions (eg, cardiovascular or lung disease) that are contraindications to nicotine use. All participants provided written informed consent for this Institutional Review Board (IRB)-approved protocol approved by the University of Southern California Institutional Review Board.

Design and Procedure

Following eligibility confirmation, participants were first randomized between-subjects to either pouch or gum product type conditions. After successful shipping of study products, participants completed a single-blind test procedure involving self-administration of eight different ONPs of a single product type (ie, either eight gum ONPs [four in fruit and four in mint flavors] or eight pouch ONPs [four in fruit and four in mint]; all products included 4 mg nicotine strength), constituting a flavor (fruit vs. mint [within-subjects]) × ONP type (gum vs. nicotine pouch and brand [between-subjects]) mixed-factorial study design. The eight ONPs were presented in a random order; each participant was assigned a sequence based on random selection of the universe of all possible sequences of the eight products. Products were presented to participants in non-descript packaging, including a label displaying only a letter, to ensure participants were blinded to the product brand and flavor (ie, single-blind), while experimenters were aware of this information. Participants completed demographic and tobacco product use surveys between product administration blocks (four products per block, two blocks separated by a 20-minute period). This 2-hour virtual video-conferenced laboratory session applied procedures successfully used for virtual studies of e-cigarette product appeal previously.³⁹

During each administration, participants were provided with instructions by the research staff on how to use each randomized ONP. Participants in the nicotine gum group were instructed: “Nicotine gum is not like regular chewing gum. To use it correctly, bite down slowly on the gum until you feel a tingling in your mouth. Then ‘park’ the gum between the inside of your cheek and your gums. Hold it for about a minute to let the nicotine absorb into your body. Then repeat this ‘chew’ and ‘park’ process, occasionally changing where you ‘park’ the gum in your mouth. You will be trying this product for 5 minutes. I will tell you when each minute has passed.” Participants in the nicotine pouch group were instructed: “To use this product, place it between your upper lip and gum. It fits comfortably in the mouth and does not require spitting. As the nicotine is absorbed through the gums, you can keep one pouch in for up to 60 minutes. You will be trying this product for 5 minutes. I will tell you when each minute has passed.” After instructions, participants were asked to keep the respective ONP in their mouth for 5 minutes (same duration for pouch and gum). Each sequence was separated by a 5-minute period during which participants were asked to rinse their mouths with water to cleanse their palates and prevent sensory carryover across trials. Because participants lacked significant ONP experience, we selected a short (5-minute) duration for each product administration to prevent the risk of unpleasant experiences that could arise from the magnitude of nicotine delivery or other experiences that could accumulate across eight longer trials of products.

Materials

The 16 products used in this study were all 4 mg nicotine: Lucy Gum (Wintergreen and Pomegranate), Nicorette Gum (Uncoated Mint, Spearmint Burst, White Ice Mint, and Fruit Chill), Solace Gum (Fruit Medley), Rogue Gum (Fruit), On! Pouch (Wintergreen and Mint), and Velo Pouch (Spearmint, Peppermint, Dragon Fruit, Citrus Burst, Black Cherry, and Citrus). ONP brand and flavor selection was based on the availability of 4 mg products that fit the designated fruit and mint flavor categories.

Outcome Measures

After each ONP administration, participants rated three dimensions of appeal and seven sensory attributes. The following items used in previous research on e-cigarette sensory attributes and appeal^17–22,37 were supplemented with new items unique to oral sensory experiences. The appeal items include: (1) “How much did you like the product?” (100 mm Visual Analogue Scale [VAS], 0–100 with “Not at all” to “Extremely” as anchors) (2) “How much did you dislike the product?” (VAS, “Not at all” to “Definitely”); (3) “Would you use the product again?” (VAS, “Not at all” to “Extremely”). The sensory experience items include: (1) “How sweet was the product?” (VAS, “Not at all” to “Extremely”); (2) “How bitter was the product?” (VAS, “Not at all” to “Extremely”); (3) “How smooth was the product?” (VAS, “Not at all” to “Extremely”); (4) “How harsh was the product?” (VAS, “Not at all” to “Extremely”); (5) “How strong was the flavor of the product?” (VAS, “Not at all” to “Extremely”). The new items specific for oral sensory experience include: (1) “How much did the product tingle in your mouth?” (VAS, “Not at all” to “Extremely”); (2) “How strong was the burning sensation in your mouth?” (VAS, “Not at all” to “Extremely”). Following a method previously used in assessing the appeal of e-cigarette,^17,38,40 composite appeal was calculated by averaging “Liking,” “Disliking” (reverse-coded), and “Willingness to Use Again.” Each of the remaining items were analyzed separately rather than combined into scales, allowing for a comprehensive examination of each aspect of the sensory experience across the various ONPs tested in the study.

Participant Characteristics

Participants reported demographic, vaping, and smoking characteristics. The Hooked on Nicotine Checklist (HONC)⁴¹ for e-cigarettes and/or cigarettes were also administered (range: 0–10), as appropriate (ie, dual users got both versions of the HONC; See Table 1 for details).

Table 1.

Participant Characteristics (N = 23)

Variables	N (%) or M (SD)
Age, M (SD)	25.5 (2.5)
Gender identity, N (%)
Man	10 (43.5)
Woman	11 (47.8)
Another gendera	2 (8.7)
Sexual identity, N (%)
Straight/heterosexual	13 (59.1)
Another sexual identityb	9 (40.9)
Race/ethnicity, N (%)
American Indian or Alaska Native	1 (4.5)
Asian	3 (13.6)
Black or African American	1 (4.5)
Hispanic, Latino, or Spanish origin	4 (18.2)
Non-Hispanic, White	12 (54.5)
Another race/ethnicity	1 (4.5)
Educational attainment, N (%)
High school diploma/GED or less	2 (9.1)
Some college completed or currently enrolled	5 (22.7)
College degree or higher	13 (59.1)
Not currently enrolled in school	2 (9.1)
Employment status, N (%)
Full-time	12 (54.5)
Part-time	4 (18.2)
Unemployed	2 (9.1)
Student	4 (18.2)
Current tobacco use status
Current e-cigarette use (with no history of cigarette use), N (%)	8 (34.8)
Current e-cigarette use (with history of cigarette use), N (%)	9 (39.1)
Current dual use of e-cigarette and cigarette use, N (%)	6 (26.1)
HONCc, M (SD)	5.7 (3.0)
HONC: Cigaretted,e, M (SD)	5.4 (3.2)
No. days used e-cigarettes in past 30 days, M (SD)	25.5 (7.7)
No. years used e-cigarettes in lifetime,e  M (SD)	3.7 (4.8)
No. days used cigarettes in past 30 days, M (SD)	25.5 (7.7)
No. years used cigarettes in lifetime,e  M (SD)	4.7 (4.8)

Frequencies may not sum to the total due to different patterns of missing data across variables.

HONC = hooked on nicotine checklist.

^aTransgender, non-binary/genderqueer, or something else.

^bBisexual (n = 4), lesbian (n = 1), pansexual (n = 3), or prefer not to answer (n = 1).

^cHooked on Nicotine Checklist: E-cigarette (range: 0–10).

^dHooked on Nicotine Checklist: Cigarette (range: 0–10).

^eAmong subsample that smoked cigarettes.

Data Analyses

To assess the first aim, fixed effects of product type and flavor on sensory and appeal ratings were tested using multilevel modeling (MLM), which accounts for the nesting of trials within participants. Ratings from each trial were examined as separate data points (eight trials per participant). MLMs were separately tested for the appeal composite and each sensory outcome. We further examined the interaction effects of product type with flavor on sensory and appeal outcomes to test whether the effect of product type is moderated by flavor. To assess the second aim, we tested the fixed effects of each ONP brand-flavor variant by constructing 16 separate binary variables contrasting the index product to all other products (eg, Lucy Pomegranate vs. all other 15 products except for Lucy Pomegranate), with separate model sets tested for each ONP brand-flavor variant binary variable. These yielded effect estimates indicative of the mean difference in appeal sensory ratings of each ONP brand-flavor variant relative to the average of the fifteen brands (range: −100 to 100). To assess the third aim, we calculated bivariate correlations between sensory and appeal ratings using Pearson’s r coefficients to examine associations among study outcomes using trial-level data, resulting in overall associations aggregated across the 16 ONPs (tertiary aim). Results were presented as unstandardized effect estimates (B) representing the mean difference in ratings across study conditions with 95% confidence intervals. There were no trial-level missing data. The significance threshold for all outcomes was 0.05 (two-tailed). Given that this is an initial feasibility study, we did not adjust for multiple testing to avoid overlooking potentially important results that could be followed in future fully powered replications. All statistical analyses were performed in R version 4.2.0 lme4 package.

Results

Table 1 displays participant characteristics. Of the 23 participants (M[SD] = 25.5[2.5] years, M[Standard Deviation (SD)] HONC-EC = 5.7[3.0]), approximately 40% currently used e-cigarettes (and formally used cigarettes), followed by participants who currently used e-cigarettes (and never formally used cigarettes; 34.8%), and participants who currently dually used both e-cigarettes and cigarettes (26.1%). Participants reported an average of 25.5 (SD = 7.7) days of e-cigarette use in the past 30 days, with a mean total of 3.7 (SD = 4.8) years of e-cigarette use. Additionally, of the six participants who used cigarettes (ie, dual users), participants reported a mean of 5.3 (SD = 9.5) days of cigarette use in the past 30 days, and 4.7 (SD = 4.8) total years of cigarette use. The sample was socio-demographically diverse (47.8% female, 59.1% straight/heterosexual, 54.5% White, 59.1% college graduated, 54.5% full-time employed).

Effects of Product Type and Flavor on Appeal and Sensory Attributes

Presented in Table S1, ONP gums (vs. pouches) produced significantly higher ratings of sweetness (B = 19.5, 95% CI = 4.3, 34.7) and strength of flavor (B = 25.6, 95% CI = 12.2, 39.0) and lower ratings of tingling sensation (B = −14.0, 95% CI = −27.8, −0.2). Fruit flavor (vs. mint) yielded a significantly higher rating of sweetness (B = 12.9, 95% CI = 6.1, 19.7) and a lower rating of a burning sensation (B = −12.0, 95% CI = −19.5, −4.5). ONP product type and flavor were not significantly associated with composite appeal scores. As depicted in Figure 1 and Table S2, we found significant interaction effects of ONP product type and flavor on sweetness (B = 15.5, 95% CI = 2.2, 28.9), flavor strength (B = 20.5, 95% CI = 5.9, 35.1), burning sensation (B = 19.3, 95% CI = 4.5, 34.0), and harshness (B = 15.4, 95% CI = 2.2, 28.5). The direction of interaction effects potentially indicated the enhancing effects of gum versus pouch product type on sweetness and strength of flavor were stronger for fruit than mint flavor, and the greater burning sensation and harshness for pouch than gum ONPs were stronger for mint flavor than for fruit flavor. However, additional work is needed to determine whether these results reflect variations in the inherent characteristics of the products rather than an enhancement effect. A sensitivity analysis found no significant differences in ratings between the first and fourth trials, suggesting no evidence of carryover effects or sensory habituation or sensitization across trials.

Figure 1.

Mean Appeal and Sensory Attribute Ratings, by Product Type and Flavor.

Appeal composite score = Average of “liking,” “disliking,” (reverse-scored) and “willingness to use again” (range 0–100).

Effects of Each ONP Brand on Appeal and Sensory Attributes

Figure 2 displays the relative difference in mean appeal score for each ONP brand-flavor variant compared with the collapsed average across the fifteen other ONP brands. Nicorette White Ice was most appealing, producing ratings that were 24.4 (95% CI = 10.5, 38.4) points significantly higher in appeal than the mean of the fifteen other ONP brand-flavor variants. In contrast, Rogue Fruit (B = −26.9, 95% CI = −40.7, −13.2) and Nicorette Mint (B = −15.0, 95% CI = −29.1, −0.8) were least appealing. Relative differences in mean sensory experience ratings for each ONP brand compared to the collapsed average across the fifteen other ONP brands are reported in Table S3 and show some variance across specific brand-flavor combinations.

Figure 2.

Relative difference in mean appeal composite score of each brand compared to the combined mean appeal of the other brands, rank ordered.

Appeal composite score = Average of “liking,” “disliking,” (reverse-scored) and “willingness to use again” (range 0–100).

x-axis = difference from mean (95% CI); y-axis = brand.

*Rating significantly different from the mean ratings of the fifteen other brands (p < .05).

Correlations Between Sensory and Appeal Ratings

Correlations between sensory and appeal ratings aggregated across the 16 different ONPs are presented in Figure 3. Appeal was positively correlated with sweetness (r = 0.35), smoothness (r = 0.54), and strength of flavor (r = 0.25) and negatively correlated with harshness (r = −0.27) and bitterness (r = −0.33). Appeal was not correlated with tingling and burning sensations. Amongst sensory attributes, sweetness, smoothness, and strength of flavor were positively correlated with each other (r-range = 0.22–0.59). Harshness and bitterness were positively correlated with each other (r = 0.43) and with burning sensation (r-range = 0.54 and 0.23, respectively) but were inversely correlated with smoothness (r-range = −0.42 and −0.35, respectively). Both tingling and burning sensations were positively associated with sweetness, and a greater burning sensation was linked to a higher strength of flavor (r = 0.29) and tingling sensation (r = 0.29).

Figure 3.

Correlation matrix between appeal and sensory attribute ratings.

Appeal composite score = Average of “liking,” “disliking,” (reverse-scored) and “willingness to use again” (range 0–100). Correlation range: −1 to 1. Strength = Strength of flavor.

x = Statistically non-significant (ps > .05).

Feasibility and Acceptability Ratings

Participant feedback indicated that the study session and products were generally well-received, with potential adjustments needed for the number of products sampled (see Table S4).

Discussion

This single-blind experiment among young adults who use e-cigarettes is the first known controlled study on the determinants of inter-product variation of ONP user experience, among a wide spectrum of ONPs. Because all products were removed from their packaging in this paradigm, this study held constant exogenous determinants of appeal (eg, marketing) and participants based their subjective judgments of appeal primarily on sensory experience. We found that gum ONPs were perceived as having a stronger flavor, greater sweetness, and less tingling sensation compared to nicotine pouches in this study. We also found that ONPs with fruit flavors were rated as sweeter and produced less burning sensation compared to ONPs with mint flavors. Interactions between product type and product flavor revealed that some of the pleasant sensory attributes (eg, sweetness and strength of flavor) favoring gum over pouch ONPs were more pronounced in fruit flavors, and some of the negative sensory attributes (eg, burning sensation and harshness) of pouch compared to gum were amplified in mint variants. These findings align with the study’s observation that ONP appeal was positively associated with sweetness, smoothness, and the strength of the product flavor. Critically, multiple brands were tested, undercovering diverse perceptions of appeal across different brand-flavor combinations. While Nicorette White Ice generally received positive ratings, Rogue Fruit and Nicorette Mint garnered less favorable ratings among participants.

An interpretation of gum ONPs being preferred over pouches is that young adults may prefer ONPs that are akin to a traditional (non-nicotine) candy gum experience versus the unfamiliarity of holding a pouch in between the lip and gums. In this study, fruit-flavored gums were particularly perceived as sweet and appealing, raising the possibility that ONPs that stimulate orosensory perceptions of sweetness and fruitiness could be appealing for young adults. While a mint-flavored gum (Nicorette White Ice) produced the highest raw ONP appeal scores, caution is warranted in interpreting it to be significantly more appealing than the other studied ONPs due to limitations in conducting pairwise product comparisons stemming from sample size constraints. Given that youth and young adults prefer mint- and fruit-flavored variants of e-cigarettes and other tobacco products,^26,42 these ONP flavors could appeal to this population similarly to other tobacco products. Considering that the use of flavored tobacco products may be associated with dual and poly use of tobacco products,⁴³ this study gives credence to developing evidence-based policies targeting flavors in new commercial ONPs to curb use by young adults—a vulnerable population.⁴

ONP pleasant flavor sensory characteristics (ie, sweetness, smoothness, and strength of flavor) were positively correlated with appeal and other types of sensory experiences. Similarly, undesirable attributes (ie, harshness and bitterness) were found to be negatively correlated with appeal. Flavors in e-cigarettes have been shown to increase product appeal, in part by masking the harshness of nicotine.^5,44 Findings indicate that flavors in ONPs could have a similar impact and encourage young adults to continue ONP use after the initial trial.⁴⁴ As these correlational analyses of sensory attributes with appeal included all 16 brand product variants, it is possible that any ONP product characteristic that leads to a pleasant sensory profile may contribute to its appeal among young adults who vape, independent of the ONP type and brand. While this insight can inform regulatory strategies to reduce the appeal of ONPs by limiting flavors or other elements that enhance sensory satisfaction, it is important to recognize the potential harm-reduction benefits of ONPs relative to vaping or combustible smoking. Regulatory efforts will need to strike a balance—making ONPs less appealing to non-nicotine using youth while preserving their potential to reduce exposure to harmful chemicals for those already using more harmful nicotine products.

One gum product (ie, Nicorette White Ice) sold as an FDA-approved nicotine replacement therapy was highly appealing among young adult e-cigarette users in this study. It is possible that this finding reflects Nicorette’s time and resources invested in product research and development as they have a longstanding place in the smoking cessation market,⁴⁵ and may have refined this smoking cessation gum flavor to offer an appealing user experience. While there was variance across ONP gum brand-flavor combinations, this study observed that some commercial ONPs and FDA-approved smoking cessation gums had similar subjective user experience appeal ratings. Yet, the adoption of smoking cessation ONPs among young adults is not common,⁴⁶ while the use of commercial ONPs among young people is on the rise.⁵ Thus, these ONPs may differ in key ways other than merely user experience that make commercial ONPs more likely to elicit problematic use patterns in young people. For example, like e-cigarettes,⁵ some commercial ONP brands use social media influencers to market products.⁵ Additionally, new ONPs have sleek packaging and come in a wide variety of appealing flavors (eg, pomegranate, mint, cinnamon).⁵ These ONP brands often use marketing strategies (ie, “It tastes like happy”; “Use nicotine to enhance focus, boost your energy, or relax”; “Enjoy the nicotine you love without getting noticed”) intended to position them as supplements to e-cigarettes and other tobacco products or to be used when vaping or smoking is not possible.^47,48 Availability and price may also influence young adults’ adoption and naturalistic use. The lower cost of commercial ONPs relative to FDA-approved smoking cessation ONPs may make commercial ONPs more accessible to young adults. Additionally, commercial ONPs are marketed widely across various store types, including some store types where smoking cessation ONPs are not sold (eg, convenience stores and gas stations). Thus, extraneous factors beyond user experience due to the product characteristics should be considered when interpreting differences in commercial ONP and smoking cessation ONP uptake.

This study supports a novel methodology for efficiently testing ONP product characteristic effects on sensory qualities and user appeal. Participant feasibility and acceptability ratings indicated the study session and products were well-received, though reassessment of the number of products tested per session may be needed. Instructions for product use were easy to understand, and participants found the product rating measures clear and sensible. The study’s design, featuring experimental control and multivariate outcome data analyzed with multilevel modeling, increases data points and statistical power. Extending this platform to study more varied outcomes (eg, physiological responses) and different user populations (eg, experienced vs. new ONP users) could enhance the external validity of these results.

This study had limitations. First, while this study examined multiple brands of commercial ONPs and FDA-approved smoking cessation ONPs with 4 mg nicotine, certain widely sold ONP brands (eg, Zyn) and products varying in nicotine strength were not included. Thus, results may not generalize across other brands or nicotine strengths. Second, we utilized a standardized approach to administer each ONP. Using both standardized and ad libitum ONP procedures in future studies could provide more valuable insights, as individuals’ perceptions of products may vary when compared to a controlled laboratory setting. Additionally, the brief duration of use of each product in this study (ie, 5 minutes) was applied for practical purposes and does not align with the manufacturer’s recommended usage for longer durations. This difference may limit the observation of changes in sensory attributes over time or how these attributes interact with nicotine delivery into the bloodstream. Future studies should consider longer use periods to better assess these dynamics. Similarly, the differences in product use instructions across product types could have contributed to pouch versus gum appeal differences. This study’s background information about pouches presented to participants in the pouch condition mentioned that these can be used for up to 60 minutes, before offering the instructions for the study protocol that involved use trials that lasted 5 minutes each in duration. This could have primed expectations of participants in the pouch condition that they were experiencing an abbreviated trial of each product. Future studies should consider longer use periods with standardized instructions to better assess these dynamics. Lastly, this study did not assess the appeal of the products based on other characteristics (eg, product packaging). These additional factors could potentially influence the way products are perceived and their overall appeal among users.

In this initial application of a novel human laboratory ONP product appeal testing methodology, fruit-flavored commercial gums produced high sensory perceptions of sweetness, more flavor, and low harshness during a 5-minute use period and appreciable appeal among young adults who use e-cigarettes. To the extent to which appeal in the laboratory translates to persistence of use after the initial trial, some ONPs could encourage young adults who use e-cigarettes to adopt dual use of ONPs and e-cigarettes, which warrants further investigation to inform evidence-based regulatory policies.

Supplementary Material

Supplementary material is available at Nicotine and Tobacco Research online.

Funding

Research reported in this publication was supported by the National Cancer Institute and the FDA Center for Tobacco Products (CTP) under award no. U54CA180905, National Cancer Institute under award no. R01CA229617, National Institute on Drug Abuse under award nos. K24DA048160 and K01DA055073, and the National Heart, Lung, and Blood Institute (K01HL148907). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the FDA.

Declaration of Interests

None declared.

Contributions Summary Statement

APT, JM, EAV, and AML designed this study. APT and AML obtained funding support for this manuscript. NP, APT, and AML drafted the initial manuscript draft. NP and RW led data collection for the study. DHH conducted all statistical analyses. All authors contributed to the editing, reviewing the manuscript versions, and have read the final version of this manuscript.

Author Contributions

Natalia Peraza (Investigation [equal], Project administration [equal], Writing—original draft [lead]), Dae Hee Han (Formal analysis [lead], Writing—review & editing [equal]), Reid C. Whaley (Investigation [equal], Project administration [equal], Writing—review & editing [equal]), Erin Vogel (Conceptualization [equal], Writing—review & editing [equal]), John Monterosso (Conceptualization [equal], Writing—review & editing [equal]), Maria Gonzalez Anaya (Writing—review & editing [equal]), Devaki J. Patel (Writing—review & editing [equal]), Nikki Jafarzadeh (Writing—review & editing [equal]), Kurt Hong (Writing—review & editing [supporting]), Tyler Mason (Writing—review & editing [equal]), Alayna Tackett (Conceptualization [equal], Funding acquisition [lead], Investigation [equal], Methodology [equal], Resources [equal], Supervision [equal], Writing—original draft [equal]), and Adam Leventhal (Conceptualization [equal], Funding acquisition [lead], Investigation [equal], Methodology [equal], Resources [equal], Supervision [equal], Writing—original draft [equal])

Data Availability

Data will be made available upon request.