What are EtG and EtS?
EtG forms through glucuronidation; EtS forms through sulfation. Both represent minor pathways of ethanol metabolism and can remain detectable after ethanol itself is gone.
Why laboratories may measure both
Agreement between EtG and EtS can strengthen the interpretation of recent ethanol exposure. Discordant results may prompt a review of cutoff levels, sample handling, analytical method, or potential contamination rather than an automatic conclusion.
Do EtG and EtS have the same detection window?
Their windows overlap, but concentrations and analytical cutoffs are not interchangeable. A laboratory report should be interpreted using the stated analyte, units, method, and threshold.
Can either test show impairment?
No. EtG and EtS can persist after ethanol is gone, so neither measures current intoxication. Blood or breath ethanol has a different purpose and time frame.
Evidence and limitations
This guide summarizes primary research and public-health guidance. Group-level findings cannot predict one person's result.