Nicotine is a naturally occurring organic compound. It is an alkaloid, a family of nitrogen-containing chemicals that includes caffeine, quinine, and morphine. Nicotine has potent stimulating effects on the human body, even though it only accounts for about 5 percent of a typical tobacco plant. An average cigarette contains from 10 to 20 milligrams of nicotine.
Nicotine passes quickly into the brain, usually within seconds after a puff. Stopping the use of nicotine is extremely difficult for most people. Nicotine cessation programs and advice on quitting are well represented in the blogosphere. Common approaches to quitting include nicotine replacement therapy, medication, and counseling. Stress and anxiety are frequent triggers for relapse into nicotine use.