Urine Drug Test: Purpose, What to Expect, and Results (2024)

Key Takeaways

• Urine drug tests check for various drugs and medications - Jump to Section
• Detects drugs like marijuana, cocaine, amphetamines, and more - Jump to Section
• Detection times vary based on drug type and user factors - Jump to Section
• Very accurate, with some potential for false results - Jump to Section
• Results need careful interpretation, considering many urine properties - Jump to Section

What is a Urine Drug Test?

Urine drug tests screen for certain medications and drugs.

This type of test is most commonly used to detect substance use issues and banned substances in the workplace.

Doctors sometimes request a urine drug screen if they think a patient has been using illegal drugs or misusing prescription drugs.

Additionally, emergency services staff members use urine drug screenings when they suspect someone’s strange or dangerous behavior might be linked to being under the influence of drugs.

Urine drug test detect a variety of substances, including:

Urine drug tests are an alternative to breath or blood tests when alcohol use is suspected. This type of test can also detect nicotine and cotinine, which is produced when the body breaks down nicotine.

Uses & Types of Urine Drugs Tests

Urine drug tests help with employment decisions. They can also be used to monitor drug use in recovery programs and other court-ordered rehabilitation programs.

If you are ordered to undergo urine drug testing, you’ll be instructed to undergo drug tests within the assigned time frame. This is done to ensure people who have legal issues don’t use illicit drugs.

Workplace drug testing is used prior to an employment offer. It may also be used periodically with random drug tests throughout the course of someone’s employment.

There are two types of urine drug tests, including:

1. Immunoassay

Benefits of this test include:

• Cost-effective
• Fast results
• Unable to detect certain opioids
• Risk of false-positive results

2. Gas Chromatography/Mass Spectrometry

Benefits of this test include:

• Used to confirm positive immunoassay
• More expensive
• Slower results
• Low risk of false positive results

Both urine testing options pose a risk of false-negative results and might not detect same-day drug use.

What Drugs Can Be Detected in a Urine Test?

Urine drug tests are one of the most reliable methods of detecting drugs in someone’s body.

The two methods urine testing listed above can detect most commonly used drugs, including:

• Cocaine
• Marijuana
• Opiates, including heroin, codeine, and morphine
• Phencyclidine (PCP)
• Amphetamines, including meth

Expanded panel drug tests detect additional substances, including:

Some urine tests detect alcohol—but are not as reliable as other drug testing methods for alcohol.

How Long are Drugs Detected in a Urine Test?

How long a drug is detectable in a urine test varies based on several factors:

• Half-life of the drug
• Body mass and metabolism
• Frequency of drug use
• Subject’s hydration level
• Method of administration
• Drug cut-off level
• Medical conditions of the test subject

These variations mean two people using the same drug can have different results. This is true even if they take the same drug test at the same time after using the same amount of a drug.

Knowing exactly how long you’ll test positive for a drug in a urine test is challenging.

On average, detection times are as follows:

• Marijuana: 3 to 30 days depending on frequency of use
• Amphetamines: 2 days
• Benzodiazepines: 3 days to 6 weeks
• Cocaine: 4 days
• Codeine: 2 days
• Heroin: 2 days
• Hydrocodone: 4 days
• Methadone: 3 days
• Methamphetamine: 2 days
• MDMA: 2 days
• Morphine: 2 days
• Oxycodone: 3 days

How Accurate are Urine Drug Tests?

Modern-day urine tests are very accurate. They are just as accurate as saliva or oral fluid drug testing.

No urine drug screens are perfect, but these drug tests are the best option available for ensuring someone is drug-free.

Additionally, since the Gas chromatography–mass spectrometry (GC-MS) drug test confirms the immunoassay test, there is an opportunity to double-check someone’s positive result.

The tests err on the side of caution in favor of the test subject. This means it is more likely to get a false negative than a false positive.

What are the Limitations?

Immunoassay tests have more limitations than Gas chromatography–mass spectrometry (GC-MS) tests.

The former produces more false positive and false negative results than the latter. A follow-up GC-MS drug test must confirm positive immunoassay results.

It’s also important that someone evaluating the drug test knows how to do so properly. The interpreter must understand detection times, cut-off values, and false-positive results.

Tests have a difficult time identifying designer drugs and continuous changes to other synthetic drug formulas.

Which is Better: Saliva or Urine Drug Test?

Whether saliva or urine tests are better varies based on the circ*mstances.

Both are comparably accurate. But urine tests can detect a wider range of substances and work faster. Saliva tests are more convenient and less invasive.

How Urine Drug Tests Work & What to Expect

Urine drug tests are usually conducted in a laboratory. This means that, in many cases, you’ll go to an off-site testing facility to submit your sample.

You’ll submit a sample to the lab technician, sometimes urinating with supervision, and then the tech conducts the test.

The test involves dipping a paper test strip into the urine to absorb the liquid. If there are drugs in the urine, the test strip will or will not change to a color indicating a reaction to different substances.

Additional tests are then performed, including a confirmatory analysis of the urine. All results must be consistent to allow for a conclusion.

Before the Test

People undergoing a urine drug test must provide a substantial sample of urine, midstream, into a disposable, uncontaminated container.

In the days before the test, it’s important to avoid alcohol and drugs. Also, eat a moderate diet with a normal fluid intake.

What you eat has a significant impact on your urine sample. For example, eating a lot of meat reduces the pH of your urine, while dairy elevates the pH.

While you need to drink enough to produce a sufficient sample for the test, you shouldn’t drink excessively. Doing so dilutes your urine and makes it more difficult to test.

Avoid excessive standing or straining before providing a sample. This can increase the risk of orthostatic proteinuria.

It’s also important to abstain from sexual intercourse for at least 24 hours before testing because the presence of sperm prevents an accurate urine assessment.

It’s also best to avoid testing during menstruation and for two days before and after. The presence of red blood cells makes it impossible to obtain reliable results.

During the Test

The best urine specimen comes from morning urine produced after eight hours of sleep or at least four hours since the last urination. This prevents functional proteinuria.

Hands and genitals should be washed before testing and the sample should be taken mid-stream.

After the Test

Once the test subject submits a sample, the lab tech labels it properly and delivers it to the collection point/testing location as soon as possible. Refrigeration is recommended until testing can occur, but the sample should not be frozen.

Test results are usually available within a few days. In some cases, same-day testing is possible. Negative tests are returned faster than positive because of the need for follow-up testing after a positive result.

If you are undergoing workplace drug testing and you test positive for prescription drugs, the lab will contact you about your medical situation. They’ll determine if you have a doctor's permission for using certain prescription medications before reporting the results to the employer.

How to Interpret Results

Drug test results must be properly interpreted, especially if the result is positive. Clinics and technicians evaluating tests should be familiar not only with reading results, but also know basic information about urine.

For example, normal color, how urine changes throughout the day, normal pH, and the importance of temperature of the urine specimen.

These factors change based on exposure to medication, certain foods, diseases, and other factors. Technicians must note these factors and consider them when interpreting test results.

Subjects taking a urine test can adulterate the test with certain substances. For instance, vinegar, salt, and lemon juice all affect the urine sample. There are also commercial products available that make the presence of drugs in a urine sample.

Sometimes this happens when someone is struggling with substance use or wants to hide their drug use from their employer. Some substance use treatment programs also conduct random drug tests.