Nicotine is a natural alkaloid found in tobacco that belongs to the nightshade family of plants and is commonly used as a stimulant and anxiolytic. Nicotine is used medically to help people quit smoking during withdrawal. Nicotine is extremely addicting and should only be used in slow-release form. Tobacco smoke contains monoamine oxidase inhibitors, which may intensify nicotine's addictive characteristics. A typical cigarette contains nearly 2 mg of nicotine. Nicotine addiction is characterised by obsessive usage, drug-reinforced behaviour, and relapse. Tolerance, sensitization, physical dependency, and psychological dependence can all lead to distress. Nicotine withdrawal symptoms include difficulties concentrating, sleep disruptions, depression, tension, anxiety, and irritability.