Diagnosis

Cannabinoid Screen and Confirmation (Urine)

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Does this test have other names?

Marijuana screen, drug abuse screening test (DAST), marijuana drug test (urine), drug abuse test 


What is this test?

This is a two-part urine test to look for delta-9-tetrahydrocannabinol (THC). THC is the active ingredient in marijuana. The test can find out if THC or related chemicals from marijuana called metabolites are in your urine. The test is considered quite accurate. You may have to do the urine test in a doctor's office or with a technician present.


Why do you need this test?

You may need this test as a requirement before being hired for a job. You might also have this test if you are showing signs of drug use. Your doctor may also give you this test to keep track of drug use treatment and to quickly look for any signs of relapse. Regular testing may help you recover from drug use more successfully.


What other tests might you have along with this test?

Your doctor may also order tests on samples of your hair, saliva, sweat, or blood.


What do your test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your doctor what your test results mean for you.

A positive result can mean recent and past marijuana use. The urine marijuana test will be positive if the amount of THC in the sample is more than 50 nanograms per milliliter (ng/mL). If you use marijuana but your test is negative, it could be because your THC levels are below this level. A confirmation test can be done by a more sensitive method if the screening test is positive. Confirmation tests are done to be certain that the original test result is a true result. It is done to make sure the result was not caused by a medicine or other substance affecting the test.

Urine tests can't show the exact day or hour that marijuana was last used. This is because THC can stay in your system even after you've stopped using marijuana. THC can linger on average up to 10 days for a casual user. It stays in your system for 2 to 4 weeks if you use marijuana often, and more than a month if you use it more often.


How is this test done?

This test needs a urine sample. You may need to give the sample with a medical staff member or technician in the room.


Does this test pose any risks?

This test poses no known risks. But the results may affect your job or legal standing.


What might affect your test results?

Medicines used to treat nausea from chemotherapy, such as dronabinol, give positive test results. Cannabidiol (CBD) found in a medicine used to treat seizures and some herbal supplements may also give positive results. CBD comes from the marijuana plant and may have some THC. Tell your doctor if you've been taking these medicines. You may be asked to give proof you have been prescribed the medicine.


How do you get ready for this test?

You don't need to prepare for this test. Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.

Author: Fisher, Steve

Online Medical Reviewer: Chad Haldeman-Englert MD

Online Medical Reviewer: Raymond Turley Jr PA-C

Online Medical Reviewer: Tara Novick BSN MSN

Date Last Reviewed: 04/01/2025

© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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