A Nicotine and Cotinine Urine Test is a laboratory test used to detect and measure exposure to nicotine, the addictive chemical found in tobacco products, and cotinine, which is its primary breakdown (metabolite) in the body.  Nicotine itself leaves the body quickly, but it is converted into cotinine, which stays in the body longer and is therefore a more reliable marker of tobacco exposure.  This test is commonly used to check whether a person has recently used or been exposed to tobacco or nicotine products such as cigarettes, cigars, chewing tobacco, vaping devices, or nicotine replacement therapies (patches, gums, etc.).