Quick answer
A negative result means the drug or metabolite was below the test cutoff at the time of collection — it does not prove the substance was never used.
In detail
A negative result means the target drug or its metabolite was not present at or above the assay cutoff in the sample collected. Cutoffs are set to avoid false positives from incidental exposure, which also means a negative result reflects timing and dose rather than proving a substance was never used. Detection windows differ by substance and specimen: a negative urine test collected days after use can coexist with a positive hair test that covers a longer window. Negative results are not usually confirmed, because confirmation adds cost without changing the reported outcome.
Frequently asked questions
Is a negative drug test result final?
A negative result means the drug or metabolite was below the test cutoff at the time of collection — it does not prove the substance was never used.
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