Important: These windows describe possibilities across groups, not a prediction for one person. Only a properly collected test can determine a result.
EtG is a window—not a clock
Ethyl glucuronide (EtG) is a minor, direct metabolite of ethanol. It can remain measurable in urine after ethanol is no longer detectable in breath or blood. But urine EtG does not decline on a universal schedule: the amount and pattern of alcohol use, elapsed time, urine concentration, kidney function, assay method, and reporting cutoff all affect detection.
Quick detection-time reference
| Time since drinking | Research-based interpretation |
|---|---|
| 0–24 hours | EtG is commonly detectable after recent drinking, particularly after heavier exposure. |
| 24–48 hours | Detection remains possible; sensitivity depends strongly on dose and cutoff. |
| 48–72 hours | Some samples remain positive, especially with lower cutoffs or heavier/repeated drinking, but sensitivity declines. |
| 72–80+ hours | An upper-end possibility rather than a dependable rule. Lower cutoffs and substantial exposure can extend detection. |
Why the “80-hour test” is oversimplified
“Up to 80 hours” became a memorable label, but it is not a promise that EtG will always be detected for that long. In a study of alcohol-dependent outpatients, a 500 ng/mL cutoff detected 68% of light drinking and 78% of heavy drinking at one day, with lower detection thereafter. A 100 ng/mL cutoff was more sensitive across longer windows.
This means a test can be capable of detecting some exposures at a late time while still missing many others. Capability and certainty are not the same thing.
What makes a detection window longer?
- More alcohol or repeated drinking across multiple days
- A lower reporting cutoff such as 100 ng/mL
- Differences in urine concentration and sample timing
- Individual health and renal-function differences
What research should you read?
Start with McDonell et al. for one-to-five-day cutoff performance, Jatlow et al. for dose-ranging and interpretation limitations, and the 100–500 ng/mL cutoff comparison by Lowe and colleagues.