Nicotine doesn’t care which way you take it.

The mechanism

What nicotine actually does.

Nicotine binds to nicotinic acetylcholine receptors (nAChRs) in the brain’s reward system, triggering rapid dopamine release. The effect lasts seconds. The brain adapts within hours. Dependence is built in days. By week three, the receptors expect nicotine — and feel its absence.

¹ West, R. Psychology & Health, 2017.

Combustion

Smoking is the worst of all worlds.

Burning tobacco produces over 7,000 chemicals. At least 70 are known carcinogens. Smoking causes roughly 480,000 deaths per year in the US alone — more than alcohol, illegal drugs, motor vehicles, and firearms combined. It remains the leading preventable cause of death globally.

² CDC, “Health Effects of Cigarette Smoking,” 2024.

The newer entry

Vaping isn’t safer. It’s newer.

E-cigarettes skip combustion, which avoids the worst of cigarette smoke. They are not without harm. The EVALI outbreak in 2019 produced more than 2,800 hospitalizations and 68 deaths linked to vaping. Sustained use is associated with elevated cardiovascular and respiratory risk, especially in adolescents and young adults whose lungs are still developing. Long-term effects remain unknown — the product class is younger than the average vaper.

³ CDC, “Outbreak of Lung Injury Associated with E-cigarette Use,” 2020. ⁴ Bhatta, Glantz, Am J Prev Med, 2020.

The discreet format

Pouches deliver the same nicotine, faster.

Oral nicotine pouches — Zyn, On!, Velo — bypass the lungs entirely, absorbing through the gum line. Blood nicotine levels can match a cigarette within minutes. Because they are odorless and easy to hide, use tends to be more frequent than smoking or vaping. Documented effects include gum recession, oral lesions, increased blood pressure, and elevated heart rate. The long-term oral cancer risk is not yet quantified — the products are too new for long-term data.

⁵ Mallock-Ohnesorg et al, Drug Test Anal, 2024. ⁶ Hatsukami et al, Tobacco Control, 2023.

What it shares

The product changes. The molecule doesn’t.

Cigarettes, vapes, and pouches differ in delivery, exposure, and side-effect profile. They share a single addictive substance — nicotine — and a single dependence pathway. Quitting one without addressing the other often results in switching, not stopping.

Why we built Quitly

Most quit attempts don’t include the science that actually works.

The cytisine literature spans more than four decades and 8,000+ trial participants. It’s the most-studied cessation alkaloid most smokers have never heard of. Quitly is built around the 25-day cytisine protocol — a plant-derived alkaloid with NEJM-published evidence. The research is on the compound itself, not any specific product.

Read more about the science →