How long one dose stays detectable in body?

The duration a single dose of a substance remains detectable in the body varies widely depending on the substance, the method of testing, and individual factors like metabolism and health. For example, alcohol can be detected in urine for up to 12-48 hours, while drugs like marijuana can be detectable for days to weeks. Generally, most medications can be detected in blood for a few hours to several days after administration. Always consult specific guidelines for the substance in question for more precise information.