1-methyl-4-(3-pyridinyl) pyrrole (β-nicotyrine) is a tobacco alkaloid. It is a potent inhibitor of cytochrome P450 CYP2A13 and a mechanism-based inactivator of cytochrome P450 CYP2A6.

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone or nicotine-derived nitrosamine ketone (NNK) is a tobacco-specific nitrosamine. NNK is considered to be a carcinogen. NNK induces deleterious mutations in oncogenes and tumor suppression genes by forming DNA adducts, which could be considered as tumor initiation. Meanwhile, the binding of NNK to the nicotinic acetylcholine receptor promotes tumor growth by enhancing and deregulating cell proliferation, survival, migration, and invasion, thereby creating a microenvironment for tumor growth.

Cotinine is a product formed after the chemical nicotine enters the body. Measuring cotinine in people’s blood is the most reliable way to determine exposure to nicotine for both smokers and nonsmokers exposed to environmental tobacco smoke. Cotinine is safe, non-addictive and has pharmacokinetic properties adequate for therapeutic use. Research has shown that cotinine has antipsychotic, anxiolytic, and antidepressant properties and modulates the serotonergic, cholinergic and dopaminergic systems. Cotinine behaves as a positive allosteric modulator of the nicotinic acetylcholine receptors and has anti-inflammatory effects. Cotinine is under investigation as an agent for the treatment of depression, PTSD, schizophrenia, Alzheimer's disease and Parkinson's disease.