All tobacco products contain nicotine because all natural variants of the tobacco plant contain nicotine, and the reason that these types of plants were smoked historically (e.g. tobacco in America, Duboisia in Australia) is that people found the effects of the multiple alkaloids they contain to be beneficial. read more
To me the real question is why does the tobacco plant contain nicotine and not some other more effective chemical like pyrithinins. read more
Processing tobacco for use in cigarettes tends to reduce the nicotine content, so the tobacco industry also maintains stores of liquid nicotine extracted from other crops, which can then be artificially re-introduced to the processed cigarette tobacco to restore and maintain the “desired” drug effect in human brains. read more
Nicotine is present in all tobacco products. Cigarettes that are marketed as low-tar or low-nicotine still contain nicotine. Nicotine is also present in dip, snuff, packets, chewing tobacco, cigars and pipe tobacco. read more