Quick answer
A dilute or invalid specimen is not a positive or a negative. Laboratories check creatinine, specific gravity, pH and oxidants, and may require a supervised recollection.
In detail
Laboratories run validity tests alongside the drug screen: creatinine, specific gravity, pH, and checks for oxidising adulterants. A specimen can be reported as dilute (for example, creatinine below about 20 mg/dL or specific gravity below about 1.003), invalid, or adulterated. Dilute results are common with heavy water intake and are not proof of intentional tampering. Depending on the program, a dilute or invalid specimen may be reported as negative-dilute, treated as a refusal, or require a recollection under observation. The correct response is to follow the program's recollection procedure rather than to submit another dilute sample.
Frequently asked questions
Is a dilute, invalid & adulterated results final?
A dilute or invalid specimen is not a positive or a negative. Laboratories check creatinine, specific gravity, pH and oxidants, and may require a supervised recollection.
What should I do next?
If you have a legitimate prescription or medical explanation, declare it through the Medical Review Officer. Follow the program's instructions for any recollection or retest.
Is this medical or legal advice?
No. This is general educational information about how drug testing works, not medical or legal advice. Consult a qualified professional about your situation.
Related
All result types · Detection chart · Test types · False positives