Which of the following substances has the longest detection window in urine tests?

Marijuana has the longest detection window in urine tests primarily due to its unique metabolic properties and how it is processed in the body. THC, the principal psychoactive compound in marijuana, is stored in fat cells and can remain in the body long after its psychoactive effects have worn off. This storage means that even infrequent users can test positive for several days, while frequent users may have detectable levels for weeks or even longer.

The detection times can vary depending on factors such as frequency of use, body fat percentage, and individual metabolism, but observational studies and drug testing protocols typically indicate that marijuana can be detected in urine for an extended period compared to other substances listed. For example, cocaine, heroin, and amphetamines generally have shorter detection windows, often ranging from a few days to up to a week, depending on the patterns of use and individual metabolism.

This distinction between marijuana and the other substances is fundamental in understanding drug testing procedures and the implications for users, especially in contexts such as employment and legal enforcement.