Nicotine

Lore & Background

Nicotine is a colorless to yellowish, oily liquid that readily penetrates biological membranes and acts as a potent neurotoxin in insects, where it serves as an antiherbivore toxin. Historically, it was widely used as an insecticide, and its structure provided the basis for synthetic neonicotinoid pesticides. In tobacco leaves, nicotine constitutes about 0.6–3.0% of the dry weight, with trace quantities in other Solanaceae crops such as tomatoes, potatoes, and eggplants.

Reader's Guide

Nicotine is highly addictive, and nicotine dependence is characterized by tolerance, physical dependence, psychological dependence, and withdrawal symptoms such as irritability, anxiety, and difficulty concentrating. Nicotine replacement therapy (NRT) products, including gums, patches, and lozenges, deliver the compound in slower, lower doses that are less addictive and are used medically to help people quit smoking. Nicotine itself is not classified as a carcinogen by either the International Agency for Research on Cancer or the Surgeon General of the United States, but at high doses it can cause nicotine poisoning and respiratory paralysis. It is also a known teratogen, associated with adverse developmental effects during pregnancy, and may impair adolescent neurodevelopment, though the extent of this effect in humans remains debated.

Did You Know?

• An average cigarette yields about 2 mg of absorbed nicotine, a dose sufficient to produce reinforcement and dependence while remaining far below toxic levels.
• Nicotine reduces the amount of rapid eye movement (REM) sleep, slow-wave sleep, and total sleep time in healthy nonsmokers given nicotine via a transdermal patch.
• Neonicotinoids, such as imidacloprid, are synthetic insecticides derived from and structurally similar to nicotine.