| Nicotine pouches | A small pouch is placed between the upper lip and gum. Nicotine and flavor ingredients are absorbed through the oral tissues. | Usually tobacco-free; formulations commonly contain nicotine, plant-based fibers, sweeteners, flavorings and pH-adjusting ingredients. | No combustion and no inhaled aerosol during normal use. | Buccal and sublingual absorption, generally slower than inhalation. | Check nicotine strength, moisture level, pouch size, ingredient disclosure, child-resistant packaging and market-specific labeling. | Not risk-free and addictive. Rules differ substantially by country, including product classification, nicotine limits, taxation and permitted claims. |
| Traditional oral tobacco | Loose or portioned tobacco is held in the mouth, allowing nicotine and other tobacco constituents to pass through oral tissues. | Contains tobacco. Product preparation and composition vary by category and jurisdiction. | No smoke is inhaled during ordinary oral use, but the product itself contains tobacco-related toxicants. | Absorption through the lining of the mouth. | Assess moisture, flavor profile, storage stability, warning requirements and restrictions on sale or importation. | Not harmless. Oral tobacco is associated with nicotine dependence and exposure to harmful chemicals; legal status varies widely worldwide. |
| Nicotine gum | Chewed slowly until a tingling sensation appears, then “parked” between the cheek and gum so nicotine can be absorbed. | Contains pharmaceutical nicotine rather than tobacco leaf. | No smoke or aerosol. | Oral mucosal absorption with some swallowed nicotine. | Dose selection, chewing technique, shelf life, flavor acceptance and compatibility with local medicine regulations are important. | Commonly regulated as nicotine-replacement therapy. It is intended to support smoking cessation and should be used according to local instructions. |
| Nicotine lozenges or mini-tablets | Dissolve gradually in the mouth, releasing nicotine for absorption through oral tissues. | Contains pharmaceutical nicotine and no tobacco leaf. | No smoke or aerosol. | Primarily oral mucosal absorption, with some swallowed nicotine. | Review dosage options, dissolution time, flavor, packaging, storage conditions and restrictions on sales to minors. | Usually positioned as nicotine-replacement therapy. It is not intended to be chewed or swallowed whole, and medical labeling differs by market. |
| Electronic cigarettes | A battery-powered heating element vaporizes a liquid that may contain nicotine, propylene glycol, vegetable glycerin and flavorings. | Typically contains no tobacco leaf, although nicotine may be derived from tobacco or synthesized. | Produces an inhaled aerosol rather than smoke from combustion; aerosol composition depends on device, liquid and operating temperature. | Pulmonary absorption, generally delivering nicotine more rapidly than oral products. | Evaluate battery safety, leakage resistance, coil consistency, liquid specifications, nicotine concentration and applicable import rules. | Not risk-free. Compared with combustible cigarettes, aerosol exposure may be lower for some toxicants, but long-term health effects and youth-use concerns remain important. |
| Heated tobacco products | An electronic heating system warms processed tobacco to generate an inhaled aerosol without fully burning the tobacco. | Contains tobacco. | No conventional combustion smoke, but the aerosol can contain nicotine and other chemicals. | Pulmonary absorption. | Consider device compatibility, consumable availability, charging requirements, waste handling and country-specific tobacco controls. | Not harmless. Reduced emissions of some compounds do not mean absence of risk, and regulatory treatment differs from both cigarettes and e-cigarettes. |
| Nicotine patches | A transdermal patch releases nicotine steadily through the skin over an extended period. | Contains pharmaceutical nicotine and no tobacco leaf. | No smoke or aerosol. | Transdermal absorption; delivery is slower and steadier than inhalation. | Check adhesive performance, heat and humidity stability, dosage duration, packaging integrity and medicine registration requirements. | Commonly used as nicotine-replacement therapy. It does not reproduce the rapid hand-to-mouth or inhalation experience of smoking. |