- According to the American Heart Association, nicotine addiction has historically been one of the hardest addictions to break, while the pharmacological and behavioral characteristics that determine nicotine addiction are similar to those determining addiction to heroin and cocaine.

- Nicotine has been noted to directly cause cancer through a number of different mechanisms

- Indirectly, nicotine increases cholinergic signalling, thereby impeding apoptosis (programmed cell death), promoting tumor growth, and activating growth factors and cellular mitogenic factors.

- Nicotine also promotes cancer growth by stimulating angiogenesis and neovascularization. In one study, nicotine administered to mice with tumors caused increases in tumor size (twofold increase), metastasis (nine-fold increase), and tumor recurrence (threefold increase).

- According to a study of about 77,000 pregnant women in Denmark, women who used nicotine gum and patches during the early stages of pregnancy were found to face an increased risk of having babies with birth defects.

- Tobacco use among pregnant women has also been correlated to increased frequency of ADHD. Children born to mothers who used tobacco were two and a half times more likely to be diagnosed with ADHD.

- After World War II, over 2,500 tons of nicotine insecticide were used worldwide, but by the 1980s the use of nicotine insecticide had declined below 200 tons. This was due to the availability of other insecticides that are cheaper and less harmful to mammals. Currently, nicotine, even in the form of tobacco dust, is prohibited as a pesticide for organic farming in the United States. In 2008, the EPA received a request, from the registrant, to cancel the registration of the last nicotine pesticide registered in the United States. This request was granted, and since 1 January 2014, this pesticide has not been available for sale