Drug Testing

Reviewed

A drug test looks for signs of illegal drugs or certain prescription and/or over-the-counter medicines that can be misused. It is usually done with a urine sample, but other samples may be used. The test cannot diagnose a drug use disorder. Results may be positive (drugs found) or negative (no drugs found or very small amount), and a positive result typically requires a confirmatory test. There are no known physical risks, but social, legal, or employment consequences may occur.

Preparation and collection

Tell the testing professional about any prescription drugs, over-the-counter medicines, or supplements you are taking. Avoid foods with poppy seeds, as they can show up as opiates in a drug test.

Understanding this test

Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.

  • A positive result may affect your job, sports eligibility, legal matters, or other aspects of your life.
  • False positives can occur due to certain over-the-counter medicines, prescriptions, and foods (e.g., poppy seeds).
  • A confirmatory test is needed after a positive initial test to verify accuracy.
  • This test cannot diagnose a drug use disorder (addiction).

What to do next

If your result is positive, you will likely have a follow-up confirmatory urine test. If you have questions about how the results will be used, talk with your provider or the organization requesting the test.

Evidence source

U.S. National Library of Medicine: Drug Testing

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