Why urine concentration matters
Urine is not produced at a constant concentration. Fluid intake, sweating, time of day, kidney handling, and the time since the last void can all affect how concentrated a sample is. The same amount of excreted EtG may therefore appear at different ng/mL values.
What creatinine tells the laboratory
Creatinine is a normal urine constituent often used as a concentration marker. A low value can indicate a dilute sample. Policies vary on whether a dilute negative is accepted, recollected, or interpreted with creatinine normalization.
Does drinking water clear EtG?
Water supports normal hydration but does not switch off metabolism or reliably shorten the biological detection window. Attempted overhydration can be detected and can make a sample unsuitable for interpretation.
Why calculators cannot model dilution precisely
A useful model would need the actual sample volume, creatinine, collection interval, renal status, and analytical method. EtG Calculator Pro therefore treats urine concentration as an explicit uncertainty rather than asking for a speculative hydration multiplier.
Evidence and limitations
This guide summarizes primary research and public-health guidance. Group-level findings cannot predict one person's result.