TABLE 3.
Summary of characterizing flavors (sans menthol) on nicotine use.
| Flavor | Species | Route | Concentration/Dose | Nicotine pH | Main findings | References |
| Sucrose | Wistar rats, adult males | Oral | Sucrose (0–10%) | n/a | • Rats increase consumption of nicotine when solutions are sweetened with sucrose | Smith and Roberts, 1995 |
| Nicotine (10 μg/ml) | ||||||
| “Vanilla,” “Coconut” | C57BL/6J mice, adult males | Oral | Vanilla, coconut (0.01–1%) Nicotine (40–120 μg/ml) |
7.7–7.9 | • Mice consume more vanilla-flavored (1%) nicotine solutions (60 mg/ml) than nicotine only solutions | Tannous et al., 2021 |
| • Vanilla flavor enhances oral nicotine self-administration compared to nicotine alone | ||||||
| “Retro Fruit Twist,” “Tobacco” | C57BL/6J mice, adult males | Oral | Flavors (n/a) Nicotine (30–200 μg/ml) |
Free-base | • Mice consume more fruit-flavored nicotine solutions than nicotine-only solutions (75, 100, and 200 mg/ml) | Wong et al., 2020 |
| • Mice do not show increased consumption of tobacco-flavored nicotine solutions compared to nicotine-only solutions | ||||||
| “Strawberry” | C57BL/6J mice, adolescent-adult males and females | Oral | Strawberry (Unsweetened Strawberry Kool-Aid made in 2% saccharin) | Free-base | • Adolescent mice prefer strawberry-flavored nicotine solutions over nicotine-only solutions | Patten et al., 2021 |
| Nicotine (0.1 mg/ml) | • Adolescent females show greater preference than adolescent males in this effect | |||||
| “Chocolate,” “Grape” | Sprague Dawley rats, adolescent females | Oral, intravenous (i.v.) | Chocolate (0.5% Hershey’s Unsweetened Cocoa) | Free-base | • Rats do not self-administer i.v. nicotine with contingent intraoral flavor delivery | Chen et al., 2011 |
| Grape (0.1% Unsweetened Grape Kool-Aid) | ||||||
| Nicotine (15–30 μg/kg/infusion) | ||||||
| *0.4% saccharin added to oral solutions | ||||||
| “Licorice” | Sprague Dawley rats, adult males | Oral, i.v. | Licorice (0.1, 1.0% vol/vol licorice root extract) | Free-base | • Licorice (1.0%) as a conditioned reinforcer prior to self-administration testing increases operating responding for nicotine infusions whereas unconditioned licorice does not | Palmatier et al., 2020 |
| Nicotine (7.5 μg/kg/infusion) | ||||||
| Saccharin, sucrose | Sprague Dawley rats, adult males | Oral, i.v. | Saccharin (0.32%) | Free-base | • Contingent delivery of intraoral sucrose or saccharin enhances self-administration of i.v. nicotine obtained via lever pressing | Wickham et al., 2018 |
| Sucrose (10%) | ||||||
| Nicotine (0, 30 μg/kg/infusion) | ||||||
| “Sweet flavors” – peach, watermelon, blackberry, cotton candy, cola, sweet lemon tea | Human, N = 20, 55% male, age 19–34) | Inhalation | Flavors (n/a) Nicotine (0, 6 mg/ml) |
Free-base | • Sweet-flavored e-cigarettes increase appeal ratings compared to tobacco, menthol, and unflavored e-cigarettes | Goldenson et al., 2016 |
| “Cherry Crush,” “Vivid Vanilla,” “Piña Colada,” “Peach Schnapps” | Human, N = 31, 58% male, average age = 34) *age range n/a |
Inhalation | Flavor (n/a) Nicotine (12 mg/ml) |
Free-base | • Piña Colada rated as sweetest and most liked • Sweetness is positively associated with liking • Harshness is negatively associated with liking |
Kim et al., 2016 |
| “Cherry,” “Chocolate” | Human, N = 132, 49% male, age 18–45) | Inhalation | Flavors (n/a) Nicotine (18 mg/ml) |
Free-base | • Individuals rate cherry and chocolate e-cigarettes as sweeter than unflavored e-cigarettes, but not more liked | Mead et al., 2019 |
| • Sweetness is positively associated with liking | ||||||
| • Irritation and bitterness are negatively associated with liking | ||||||
| “Cherry,” “Chocolate” | Human, N = 39, 100% male, age 18–45 | Inhalation | Flavor (n/a) Nicotine (6, 18 mg/ml) |
n/a | • Sweetness is positively associated with first puff liking | Baker et al., 2021a |
| • Harshness/irritation is negatively associated with first puff liking | ||||||
| • First puff liking is not associated with total nicotine intake | ||||||
| “Cherry” | Human, N = 19, 68% male, age 21–35) | Inhalation | Cherry (4.7% or 9.3% vol/vol) Nicotine (0, 6, 12 mg/ml) |
Free-base | • Increasing nicotine concentration increases ratings of bitterness and reduces appeal | Pullicin et al., 2020 |
| • Cherry flavor increases ratings of sweetness and liking | ||||||
| • Increasing the concentration of cherry flavor from 4.7 to 9.3% increases perceived sweetness, harshness, and bitterness but does not alter hedonic ratings |