An initial or at-home drug test can provide a preliminary screening result. It cannot always identify the exact cause of a result, and it should not be used alone to make a serious medical, employment, or legal decision.
Why confirmation matters
Screening tests are designed to identify samples that may need additional analysis. Some screening methods can react with other substances. The U.S. Food and Drug Administration advises sending a positive at-home result to a laboratory for confirmation. Federal workplace testing programs also use laboratory testing and a Medical Review Officer to review regulated results.
Learn more in the FDA’s home drug test guidance and SAMHSA’s workplace testing resources.
What to do after an unexpected result
- Read the test instructions and check that the kit was stored and used as directed.
- Ask the test provider or laboratory whether a confirmatory test is available and how to request it.
- If the result is part of a workplace or regulated program, follow that program’s review process and deadlines.
- Be prepared to discuss prescriptions and other relevant medical information with the authorized clinician or Medical Review Officer.
- Do not stop or change prescribed medication without speaking with the prescribing clinician.
Home-test limits
Home tests differ in the substances included, cutoff levels, collection method, and instructions. A negative home result is not a guarantee that every substance was tested for or detected. Check the product labeling and consult a qualified professional if the result has important consequences.
This page is general educational information, not medical or legal advice.