How your body breaks down cannabis and why it matters in court

This literature review examines how illicit drugs, including cannabis, are broken down in the body and why this matters for forensic investigations. The research focuses on drug metabolism through Phase I and Phase II processes, primarily governed by cytochrome P450 enzymes, which transform cannabinoids and other substances into metabolites that can be detected in blood, urine, hair, and other biological samples. A key forensic marker for cannabis use is THC-COOH, a metabolite produced when the body processes THC—this compound can remain detectable long after the initial effects wear off, which has significant implications for drug testing and legal investigations.

The paper highlights how individual variability in drug metabolism significantly complicates forensic interpretations. Factors such as genetic polymorphisms, differences in enzyme activity levels, and interactions between drugs can affect how quickly substances are metabolized and how detectable they become. This variability is especially relevant for cannabis users, as the detection window for THC and its metabolites varies considerably between individuals—some people may test positive for days or weeks after use due to slower metabolism or THC storage in body fat, while others clear it more rapidly.

Modern analytical techniques like liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-resolution mass spectrometry (HRMS) have dramatically improved the accuracy of drug detection in forensic contexts, with direct applications to workplace drug testing, impaired driving cases, and post-mortem investigations. For cannabis specifically, these advances enable more precise distinction between recent use and chronic exposure, though the paper emphasizes that forensic professionals must understand metabolic variability to avoid misinterpretation of results in legal proceedings.