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5.0 FAQ

Testing Procedures & Interpretation

How do I know if the test was done properly?

The presence of the control line means that there was enough specimen volume present to ensure proper migration up the drug test strip. The test should perform properly if the control line displays and the rest of the procedural instructions were followed.

How do I interpret the test results?

Please see package insert for manufacturer’s specific instructions for interpreting the test results. There will be a top control line that displays when the test is working properly (indicating proper drug test strip saturation) and a second space below where a line will either be present (indicating negative result) or absent (indicating positive results). See illustration below.
 ** Note: No meaning is attributed to Test Line (T) color, intensity or width. Very faint lines are still interpreted as Negative. **

Where can I find procedural instructions for the tests?

Instructions for the drug screens can be found on their dedicated product pages. All tests come with instructions in the box.

How do you operate the tests?

Please see package inserts for manufacturer's instructions on how to do the test. They will differ slightly from brand to brand.

Where can I find technical information on the tests?

Technical information, including cross-reactivity, accuracy rates and operating instructions can be found on the package insert available on each product page of this website. A package insert is also included in each box of tests shipped to you.

How does the test work?

The test is a lateral flow chromatographic immunoassay for the qualitative detection of an identified drug or the identified drug metabolites in human urine. For a more detailed explanation the science behind this see this article.

Does the specimen need to be confirmed by laboratory analysis?

It depends on the purpose and setting of the testing being done. Sometimes this will be necessary. The rapid test is preliminary and yields qualitative results, detecting the presence of an identified drug at or above a specific concentration (cut-off level). For confirmation and quantitative results a laboratory analysis is required. Gas Chromatography/Mass Spectrometry (GC/MS) is the preferred confirmatory method.

How should urine specimens be collected?

A clean and dry container must be used.

Can urine specimens be stored prior to testing? If so, how?

Yes. Urine specimens may be stored at 35-46 degrees Fahrenheit for up to 48 hours prior to testing. For longer storage, freeze specimens below zero. Specimens should be well thawed and mixed before any testing takes place. Urine specimen storage should not exceed 2 hours at room temperature or 4 hours under normal refrigeration.

Must refrigerated specimens reach room temperature before a test is used?

Yes. Note that specimen at body temperature does not need to reach room temperature before running the test.

Will menstrual blood interfere with the test?

No, it should not have any effect on the test.

The Test and Control lines differ in color – does this mean anything?

The shade or boldness of the line in the test region will vary. Any presence of a line (even a very faint pink one) should be considered a negative result.

Is it normal to see a red/pink fluid migrating up the test strip?

This is normal. As long as the red/pink background does not interfere with the interpretation of the results the color of the background can be ignored.

How long do you wait to read the results?

Please see package insert for manufacturers specific instructions. You will usually read the test results at 5 minutes (not before). You must always make sure a control line appears before reading the result. The control line is to ensure that the test is working properly.

When testing for adulterants (specimen validity testing or ‘S.V.T.’) the results can be read much sooner (usually after about a minute). Again, always read manufacturer’s instructions prior to testing and interpretation of results.

How long are the results stable?

See package insert for the specific test you are using. Most test results are designed to be read at 5 minutes (not before). The test results are generally stable for about an hour after testing. Specimen Validity Test results should be read immediately.

What are some factors that could cause invalid test results?

Not following proper testing procedure (always read manufacturer’s instructions prior to testing), unsealed packaging, damaged test membrane or unsuitable specimens.

What other drugs or substances will cross-react and produce a positive result?

See our cross-reactivity chart and the package insert for the drug test you're using for a detailed list of possible cross-reactants.

Does a negative result indicate drug-free urine?

Not necessarily. A negative result may be obtained when a drug is present in the urine but in an amount that is below the cut-off level of the test.

Will these tests detect adulterated urine specimens?

We do have cups and dip tests available that include a screen for adulterants (also known as Specimen Validity Tests). See catalog for all available options.

What are the screening cut-off levels?

See package insert for product you are using. Although there are standard cut-off levels, some tests are available with more sensitive cut-off levels (ex. OPI 2000 vs OPI 300).

Is there an expiration date on these tests?

Yes. As a general rule, we do not ship out tests with an expiration date of less than one year out. Most have an expiration date between 1 year and 18 months from the time of purchase. The expiration date can be found stamped on the individually wrapped tests. Stored at room temperature (not extreme cold or heat) these tests will perform exactly according to the manufacturers specifications through the expiration date.

How accurate are they?

Generally, the rates fall within 97-99+%. The accuracy rates can be found on the package inserts that come with the tests. PDF downloads of the package inserts can also be found on the individual product pages of this website.

What is the window of detection time for each drug?

There are general guidelines you can work with but there will always be some variation. This is due to many factors including frequency of use, body weight, rate of metabolism, level of hydration (urine pH), route of administration, and more. The approximate detection times can also be found on the package insert that comes with the drug screens.

General detection times (urine tests):

Alcohol: 1-3 days
Amphetamines: 2-4 days
Barbiturates: 1-21 days
Benzodiazepines: 1-7 days
Buprenorphine: 3-5 days
Cocaine: 1-7 days
Marijuana: 3 days - 1 month+
Methamphetamine: 1-4 days
Methadone: 1-7 days
MDMA: 1-3 days
Morphine: 1-3 days
Opiates: 1-3 days
Oxycodone: 1-3 days
Phencyclidine (PCP): 2-13 days
Propoxyphene: 1-7 days
Tricyclic Antidepressants: 2-15 days
K2 / Spice (synthetic cannabinoids): 1-3 days 

General detection times (saliva tests):

Within the last 60 min - 48 hours*

*Saliva Tests (oral fluid tests) help determine more recent drug use. Saliva tests can typically detect drug metabolites within 30 to 60 minutes of ingestion. Although the window of detection time does vary for each drug due to various factors the general detection range is within the last 60 min - 48 hours. One potential advantage of oral fluid testing is identifying recent usage that may be missed by urine testing because of the additional time it takes for the drug metabolites to be detectable in urine.


I just placed my order online. Now what?

You should immediately receive an order confirmation email. When the order is fulfilled (usually same day, excepting weekends) you will receive another email – and when it ships, yet another. You will also be given tracking info to follow your order from the warehouse to your front door.

When will my order ship? 

Most orders placed by 1pm EST will ship same day. Items will ship via FedEx Ground service (or equivalent). If you need to expedite shipping please call 888-562-5852 to make arrangements. For more details see our Shipping & Returns Page.

How do I track my package?

Please see our Track Your Order page. Enter your tracking # to receive detailed in-transit information.

What is CLIA?

CLIA stands for Clinical Laboratory Improvement Amendments (1988). These Amendments establish quality standards for all non-research laboratory testing on specimens derived from humans for the purpose of providing information for the diagnosis, prevention, treatment of disease, or impairment of, or assessment of health. Urine drug screen (UDS) devices fall into this category.

What are CLIA-waived tests?

Waived tests are those that the FDA has determined so simple and accurate that there is little risk of error if the test is performed incorrectly. Not all tests have been so categorized by the FDA.

Do I need to use a CLIA-waived test?

If you are not in the health care industry and are not getting reimbursed for tests performed under the CLIA program, chances are you do not need to use tests labeled as CLIA-waived.

For the list of tests granted waived status under CLIA by CPT code (G0434QW) you can use the CLIA-waived database search tool. You can also search the OTC (over-the-counter, also CLIA-waived) database by test type, manufacturer, etc. Contact us if you need any help using these tools.

Browse our selection of CLIA-waived test cups (UDS cups).
Browse our selection of CLIA-waived dip card tests

Do I need a CLIA Certificate of Waiver?

In order to process Medicare/Medical claims your facility needs a CLIA Certificate of Waiver.

On the CMS website ( you will find detailed information on how to apply for a CLIA Certificate as well as list of CLIA state agency contacts.

What are the correct billing codes to use?

HCPCS code: G0477
CPT code: 80300

What is the reimbursement amount paid out by insurance companies?

This depends on your state and the insurance payer (medicare vs. private). Consult a medical billing professional for further information.

** Disclaimer **

** ToxTests cannot guarantee reimbursement by any public or private insurance carrier and is not responsible or liable in any way for any result or consequence that follows from the use of this publicly available billing information. Refer to the Center for Medicare & Medicaid Services ( or other relevant insurance payers for up-to-date coding and state by state reimbursement information.**