Nicotine is a psychoactive alkaloid that is most commonly administered through smoking or chewing the leaves of the tobacco plant (Nicotiana tabacam and Nicotiana rustica), although starting the late 20th century nicotine gums and other products began to be widely used. Nicotine has a long history of use in its natural form and remains a widely-accepted and commonly-used psychoactive substances, despite being highly addictive and linked to serious health problems. Anti-smoking regulations and media campaigns have substantially reduced use of nicotine in Europe and North America in the last 20 years.