Nicotine is a drug in tobacco cigarettes, cigars, pipe tobacco, chewing tobacco, and some e-cigarettes. Nicotine is an addictive stimulant that causes the heart to beat faster and makes blood pressure rise. It can also make a person feel less hungry and speeds up the metabolism. These effects can be very unhealthy. Many people who use tobacco products want to quit but have a hard time quitting. It is one of the most addictive chemicals that is widely consumed by humans.
Nicotine is a substance found in most members of the Nightshade family of plants. Small quantities of it can be found in tomatoes, potatoes, aubergines (eggplants) and green pepper (Capsicum, the peppers used as vegetables). Nicotine is also in the Coca plant. In higher quantities it is a very efficient poison. It acts on the nerves. It is a stimulant in lower quantities. It is the main reason people are addicted to smoking.
Besides the treatment of nicotine dependency, it seems that the drug can also be used to treat special (severe) forms of epilepsy, as well as some other diseases.
The amount of nicotine in one cigarette varies greatly. Factors which influence the amount include type of tobacco; brand of cigarette; country or region (some markets restrict maximum average nicotine levels; and how the cigarette is smoked.