Recently, researchers have discovered the first archaeological evidence indicating that the presence of marijuana can remain in the human body for over 300 years. This finding comes from a study led by Gaia Giordano from the University of Milan, Italy. Initially, the research aimed to detect signs of drug use or 'recreational plants' (narcotics) among the population of Milan in the 17th century.

By conducting toxicology analysis, the research successfully identified the molecules tetrahydrocannabinol (THC) and cannabidiol (CBD) as psychoactive compounds of marijuana. Both substances were found in the thigh bones of men and women. After ingestion, these substances are likely to be absorbed into the bloodstream and then enter the blood vessels in the bone tissue, where they become trapped. Additionally, this finding is very recent.