Nicotine is a alkaloid found naturally throughout the tobacco plant, with a high concentration in the leaves. It constitutes ca. 5% of the plant by weight. It is a potent poison and is inlucded in many insecticides.
The substance is a powerful stimulant and is one of the main factors leading to the addiction of smoking tobacco. Although the amount of nicotine inhaled with tobacco smoke is quite small (most of the substance is destroyed by the heat) it is still sufficient to cause addiction. The amount of nicotine absorbed by the body from smoking depends on many factors including the type of tobacco, whether the smoke is inhaled, and whether a filter is used. On average it takes about seven seconds for the substance to reach the brain.
In small doses nicotine has a stimulating effect. It enters the bloodstream and promotes the flow of adrenaline, a stimulating hormone. Nicotine also speeds up the heartbeat, raises the blood pressure and reduces the apetite. In large doses it may cause vomiting and nausea. Withdrawal symptoms include irritability, headaches and anxiety. The may last for 48-72 hours.
