What is the primary carcinogen/active compound in smokeless (chewing/dipping) tobacco?

Nicotine is the primary active compound in smokeless tobacco that causes addiction. It is absorbed through the oral mucosa directly into the bloodstream, producing rapid systemic effects (stimulation, euphoria) and creating strong physical and psychological dependence. While tobacco-specific nitrosamines (TSNAs, particularly NNK and NNN) are the primary carcinogens responsible for the increased risk of oral, pharyngeal, esophageal, and pancreatic cancers associated with smokeless tobacco use, nicotine is the main chemical that drives the addiction. Carbon monoxide and tar are primarily combustion products of smoked tobacco and are not the main components of smokeless tobacco.