UZH forensic team detects GHB-pentose biomarker 13–16 hours after suspected knockout drop cases

Researchers at the Institute of Forensic Medicine of the University of Zurich (UZH) have shown that a biomarker can reveal prior ingestion of gamma-hydroxybutyrate (GHB) for longer than the drug itself can be found. The university announced the result on Tuesday, and the study appeared in the journal Drug Testing and Analysis, as reported by bluewin.ch. bluewin.chbluewin.chbluewin.chOpen source ↗

GHB is used as a recreational drug and is sometimes administered secretly to render people unconscious. It can cause disturbances of consciousness and memory lapses.

Why GHB is hard to detect

GHB is typically detectable in blood for only about six hours and in urine for about twelve hours. After that, ingestion often can no longer be established from the active substance.

When GHB is ingested, it binds with a sugar to form GHB-pentose. This compound serves as a biomarker, a biological indicator of prior GHB use. A team led by Andrea Steuer first found evidence of the marker in 2021. bluewin.chbluewin.chbluewin.chOpen source ↗

Results on urine samples

The team applied the method to 2,414 anonymized urine samples collected from 2024 to 2026. In several suspected criminal cases the method proved reliable. The researchers detected the marker 13 to 16 hours after the incidents, even though GHB levels had already dropped below the threshold.

The method also opens possibilities for unexplained deaths. GHB can form naturally in the body after death. According to the study, however, GHB-pentose forms only if the substance was ingested during life. In 20 urine samples from deceased individuals the researchers detected GHB but not the pentose compound, which suggests that these people had not ingested GHB during their lifetime.

The Institute of Forensic Medicine has already incorporated the analysis into its regular laboratory operations, according to the university. Further research is needed before definitive conclusions can be drawn about the maximum detection period in individual cases. bluewin.chbluewin.chbluewin.chOpen source ↗