When inhaled, nicotine gets to a person s brain in seven seconds, twice as fast as intravenous drugs. Nicotine affects the brain and central nervous system. It changes the level of neurotransmitters and chemicals that regulate mood, learning, alertness, and ability to concentrate. Nicotine increases the heart rate, but it constricts the blood vessels, which reduces circulation. Nicotine can act like a stimulant or a sedative, depending on the level of nicotine in the body and time of day.
Smoking also causes the release of endorphins, which create a tranquilizing effect.
A tolerance for nicotine begins to develop with the first dose. Therefore, the level of use must increase to maintain its effects and to prevent withdrawal symptoms. However, one of nicotine s baffling qualities is that its grip is not the same on everyone. Although there is genetic and biochemical research that describes some of the various and powerful effects of nicotine, such complex issues and controversies are outside of Nicotine Anonymous. These effects may be masked by how easy it is to acquire and maintain an adequate supply.