Do Drug Test Kits Expire?

Do Drug Test Kits Expire?


A drug test kit is a type of laboratory device used to analyze bodily fluids to determine if the person under suspicion has recently been using drugs, specifically illicit drugs. 

It is essential to follow the instructions for proper storage of the drug test kit to preserve its shelf life. The shelf life of a drug test kit is usually disclosed on the product label.

Table of Contents:


What is a Drug Test Kit?

A drug test kit is a type of medical device that tests for the presence of illicit substances. It consists of a collection device that collects the sample and a testing instrument, which analyzes the possible drugs.

A drug test is a standard method of confirming the suspected substance abuse, assessing the severity of use, and determining treatment needs. Many different tests can be carried out to identify if someone has any substances in their system: urine tests, saliva tests, hair follicle tests, and more.

These tests are used to test for trace levels of certain drugs in the body. Although the ability to detect drugs is proven in a laboratory setting, there is no accepted scientific consensus about how accurate these devices can be.

The accuracy of a drug test has both an external component and an internal component:-

  • The external component consists of any factors that affect the accuracy of the results of the test. 
  • The internal component consists of any factors that affect the accuracy of the test's calculation (i.e., prediction) of the amount of drugs in question. 

The external component is considered to be much more important than the internal component. It affects whether or not a person is subject to criminal prosecution, criminal penalties, or even civil sanctions.

The accuracy of a drug test can be assessed on two levels: general accuracy and quantitative accuracy.

  • The general accuracy of a drug test is concerned with whether the test gives a result which reflects reality.

Therefore, the test should return a negative result if the person being tested does not have drugs in their body and should return a positive result if the person tested does have drugs.

  • The quantitative accuracy of a drug test is concerned with how accurately it can determine how much of some substance (i.e., drug) is present. Thus, it is measured in terms of the percentage of the sample that contains the drug. 

The level of accuracy is expressed in terms of a proportion known as sensitivity.

Every drug test kit has its window period, which refers to the amount of time from the initial use of a drug and when the drug will be present in detectable levels in bodily fluids or tissues.

This period can vary widely depending on the type of drug. For example, a drug test kit that detects cocaine can detect a substance at a detectable level within 72 hours after the last use.

In contrast, a drug test kit that detects opiates can detect such drugs at detectable levels within ten days after the last use.

Who should use a drug test kit?

A drug test kit is typically used by employers, school administrators, law enforcement officials, and other individuals who seek to ensure that their employees or the general public are not involved in illicit drug activity.

Drug test kits are used in criminal investigations and clinical settings by people like medical workers during patient examinations. It can also be used to detect the presence of other types of substances with illegal intent.

Aside from government agencies, drug test kits can be used in defense communities or personal injury claims. Drug test kits are typically used in two ways.  The first type of test checks for the presence of drugs through urine or saliva, while the other type detects drugs through a blood sample or hair follicle.

The most common form of drug testing is an analysis of urine samples using immunoassay methods. Drug test kits intended to analyze urine samples can usually detect MMJ, cocaine, opiates, amphetamines, methamphetamines, and PCP.

There are additionally drug test kits that can detect the use of common drugs like nicotine and benzodiazepines. Some drug test kits can be used to analyze blood samples for the presence of opiates, cocaine, and amphetamines.

Although drug test kits may not be 100% accurate; however they can still help in several ways. Police officers, prosecutors, and defense teams use this type of data to aid in drug arrests, detect workers or clients with illegal substances, or establish whether a person is taking the prescribed medication for their illness.

Do drug test kits expire?

Yes, drug test kits expire over time and will lose their accuracy, rendering the results inaccurate. Drug test kits are designed to be used within a specific timeframe to avoid inaccuracies.

Drug test kits manufacturers generally provide expiration dates on the packaging of urine drug test kits and testing strips. Testing strips may also have an expiration date stamped on the strips themselves.

To ensure the quality of the test, users must use it before the test kit expires for the best results. Drug test kits should be stored in a dry, room temperature location away from direct sunlight, heat, and moisture.

Keeping the test kits in their sealed package after opening will help ensure quality results. Urine drug test kits and drug testing strips should not be frozen and should never be exposed to extreme heat or cold.

Test results from expired drug test kits are not guaranteed accurate, nor are they guaranteed to be comparable to the current day's standards when it comes to possible legal consequences.

What is the shelf life of the drug test kits?

Usually, the drug test kits have a shelf life of 24 months from the date of manufacture.  However, it is not a hard and fast rule because different manufacturers place different expiration dates on their products.

Therefore, some kits may have a shelf life of 5 years and some only 1 year, but generally, the expiration is 24 months. It all depends on the manufacturer's standards for testing and packaging abilities.

You should always check the packaging carefully before buying it to know how long it will be effective. So if you think you have an expired drug test kit, this should be reported to the company that sold it.

It is also essential that people don't keep drug test kits for an extended period. If you want your results to be accurate, then you must use a drug kit within the specified shelf life.


1. Urine Drug Test:

Urine tests are the most common form of testing and can be administered at home or in a laboratory. The drugs in substantial quantities are excreted through urine, so it is relatively easy to detect their presence with urinalysis.

Depending on various factors, including drug use, metabolism, regular diet, and randomness of urine, the urine test can remain positive from a few days to a month after the last drug consumption.

In addition, urine tests only detect a specific drug at the time of testing.

Procedures: A qualified medical professional supervises a urine drug test by collecting the urine sample into a particular collection container (cups are commonly used) which contains an additive that turns urine blue when exposed to certain chemicals.

The typical urine sample consists of a container that holds about 5 ml of fluid.

The results from a qualitative test can be read on the spot after only a few minutes' wait. Non-specific tests require the urine to be sent overnight to a laboratory for analysis.

Expiration: The shelf life is 18-24 months, and it can sustain in a wide range of temperatures.

2. Blood Drug Test:

Blood drug testing involves drawing a person's blood through a needle, then testing the sample for drugs. Blood drugs tests can detect drug use. As soon as the drug enters the blood, it starts showing its effects.

The blood test gives accurate results in just minutes and is quite popular among employers. However, the test is not that easy to be administered and needs experts' help.

This test is only advisable to be conducted when the employer suspects drug use on their employee. In many cases, employers resort to this procedure to check the moral conduct and control illegal substance use on their working premises.

Procedure: You can either have the sample taken from the arm's vein or collect it through a finger prick.

Expiration: The accuracy of the results can be compromised if the expiry date elapses. Usually, the kits have a shelf life of two to three years.

Note: A blood test involves invasive procedures that can cause unnecessary complications in some cases. The process may be painful for some and risky for others, so you should not go ahead with this unless you are sure that your employees are habitual drug users.

3. Hair Follicle Drug Test:

The hair follicle drug test is a comprehensive detection method for drugs in the body. It is an FDA-approved stand-alone test that can detect the use of many classes of illegal and some prescription drugs.

This method does not indicate that the person currently has used drugs, however. Instead, it suggests that a person may have used drugs in the last one to three months.

A hair follicle drug test is not a substitute for a blood or urine test. Nor does it detect all forms of drugs; it only looks for substances that the person's body has metabolized that produce drug effects in the body.

Procedure: The hair of the person being tested will be collected and examined for traces of drugs. In the event of a positive test, drug treatment and rehabilitation should take place immediately.

Expiration: The shelf life of the hair drug test kit is 24 months after production.

4. Saliva Drug Test:

Like urine tests, saliva drug tests look for drugs directly in a person's saliva. These are the basic type of drug tests, and they can be administered quickly and easily. These testing kits are used when testing employees or athletes for drugs.

Saliva tests are often referred to as "oral drug tests" because they test for drug activity in the mouth's lipid layer. The most common type of saliva testing is a rapid screening test, where saliva is swabbed manually.

Procedure: A saliva sample is taken from the inside of your mouth, and a small amount of saliva is drawn into a test tube or well using an oral swab. It takes about 5 to 10 minutes to obtain a saliva sample.

Expiration: The shelf life of any drug testing kit is usually a couple of months. Generally, the expiry date is mentioned on the backside of the package. If you notice anything unusual, discard the kit and buy a new one.

5. Sweat Patch Drug Test:

This drug test is performed by analyzing a person's sweat to detect trace amounts of MMJ, cocaine, and methamphetamine. A sweat patch drug test is one of the most reliable methods currently in use.

This type of test is used for pre-employment screening and random drug testing and to detect substance abuse. This test offers convenience and comfort because you can wear the patch anywhere. It also provides rapid results as they are detected in real-time.

Procedure: The patch is applied to the person's upper back and then covered with a protective plastic wrap. The patch remains on the skin and is removed after that period.

Expiration: The shelf life of the Sweat Patch drug test kits is about 2 years.


To a lot of people, the idea of having an inaccurate drug test kit scares the hell out of them. The last thing you want is to be falsely accused and don't have any evidence to support yourself.

No, an expired drug test kit is not considered to be accurate. An expired drug test kit will still work well, but it won't be as precise as a new one. Even if your test works as expected, these results should not be considered as a reliable result.

That's why it's so important to pay close attention to the date of expiration on the drug test kit you're about to use. This particular date is usually printed on the back of the package along with other important information.

For example, if you purchased a drug test kit on June 1, 2020, with an expiry date of June 1, 2022. In this case, if you purchase and use the drug test kit before June 1, 2022, it will work well.

Another way to tell if an expired drug test kit is working accurately is by comparing it with a new one. The new drug test kit should produce an accurate result, while the expired one won't.

To avoid any possible issues with the accuracy of a drug test kit, make sure to use only the recommended product by your employer or authority. Besides that, the packaging should also be correct and respective of where it was purchased from.

You should keep in mind that you might be denied entering your workplace or failing a drug test because of an expired drug test kit. Many employers will not allow you to enter your workplace without a reliable result from a drug test kit. Because of this, it's crucial to ensure that a drug test kit is 100% accurate.

Following are reasons why an expired drug test kit will not be as accurate:

  • Because of degradation and other unknown chemical reactions in the kit, the test will not be accurate and may give incorrect results.
  • The chemicals in the kit may change over time and thus can no longer detect drugs based on chemical reactions and color changes.
  • False positives may occur for some of the tests if the person has consumed the drug at a different time and different duration.
  • The chemical reactions involved in drug testing need to be precise as when they get mixed with certain drugs, some false positive or negative results may appear.


  1. What is the difference between urine and saliva tests?

Urine tests are the most popular form of drug testing. Saliva testing detects recent drug use because it can be collected by swabbing inside an individual's mouth with a cotton stick.

Urine tests are commonly used for workplace drug testing and employers who want to ensure that substance use is not a prelude to more severe drug misuse. In comparison, saliva testing has been criticized as relatively ineffective, expensive, and invasive than urine sampling.

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  1. How do you know when a drug test is positive?

The amount of drug metabolites in your system, along with the amount of time since the drug was last used, will determine if you have tested positive for drugs.

  1. What exactly is urinalysis?

Urine testing is the most widely used and recognized tool used by employers and health insurance companies. The test checks for the presence of drugs and is a primary screen for any drug use.

The urine screening test will detect some forms of drug use, which will also give you a positive result if you are a heavy drug user. However, urine tests are used as a preliminary step before more specific and accurate testing.

  1. I have been a long-time drug user; when can I expect my urine test to be back?

It depends on the type of drug in use and your experience level. A recent drug user may not have enough metabolites in their system to show on the test, whereas someone who has used drugs for a longer time will detect these metabolites much faster.

  1. Can I use a substitute for my urine in the test?

No, this is not possible, and the test will be negative if you try to use someone else's urine. However, the lab is aware of these tricks, making it so difficult for you to pass.

  1. How detailed is the testing lab report?

The results report will indicate the name of the drug tested for and whether it was positive or negative on the test.

Based on this information, most employers will not press for more details. However, if you have tested positive for drugs, it is important to contact experts.

  1. Why are my test results negative when I have been using drugs?

Some tests may only pick up the presence of metabolites that are formed after the drug is ingested. If a drug has been used over a long period, the metabolite levels may be too low to detect on a urine test.

However, if you test positive for recent drug use, the level of metabolites will be very high and will give you a positive result on your test.

  1. How will I know if my results are positive or negative?

You can wait 2-3 weeks after the test is finished to let you know the results.

The results will either be negative or positive, which means that there were traces of the drug detected in your system, but it was not enough to indicate drug use for at least 20 days after your last use.

  1. Can all drug tests be used to incriminate me?

No, not all drug tests can be used to incriminate you. Urine testing is the most popular drug test because it is very inexpensive, and the results are easy to interpret.

  1. What labs are used for drug testing?

Many labs are used to test for drugs. These labs have been developed to detect drug metabolites in urine, saliva, and hair follicles.

  1. When is the best time to test for drug use?

Many employers and insurance companies want you tested during the hiring process and at random times afterward, so it is essential to know these tests early on.

You should be aware of your probationary period, and if you are tested during this time, you may find that the results could lead to immediate termination.

  1. Why is drug testing done?

Drug testing is a common way to detect illegal drugs, even though many people use illicit drugs without ever being detected by a drug test. Employers want to ensure that their employees are capable of performing their job without impairments.

  1. How much time do I have to pass my drug test?

If you have a urine test scheduled, you should be ready and prepared with the necessary products 2-3 weeks before the testing date (the day before your test is scheduled).

  1. Can an employer require you to take a drug test?

Yes, an employer can require their employees to take a drug test.

  1. Can an employer require you to take a drug test regardless of whether or not you have any drug use?

No, an employer can't force their employees to take a drug test. They can only request the test.

  1. Can you get a positive drug test due to contamination?

No, this is not possible; the products are FDA-approved.

  1. Are there any other ways to test for drug use?

Yes, a hair follicle test is very popular because it shows the history of drug use by analyzing the drug metabolites in each strand of hair. Hair can be used to provide a very detailed view of the body's interactions with drugs.

It is more challenging to administer this test than a urine analysis, but it is becoming more popular as business owners are interested in the screening results.

  1. How do I pass a urine test?

There are many products available to help you pass a drug test. These products will cleanse your urine sample of any traces of metabolites, which will result in you testing negative during your test.

  1. How can I reduce my drug use without being detected?

It is essential to avoid drugs for at least 20 days before your drug test and be well-hydrated when taking the sample.


Using the wrong drug test kits can result in severe legal problems or make you a criminal suspect. This article can help you know how to use the right one and avoid problems.

You will realize that there are many different kinds of drug test kits out there, and you must use the right one for your purpose. Also, always remember that some drug test kits will be more accurate than others, so you must use one whose shelf life meets your requirements.

So, you should consider using the appropriate drug test kit for your purpose from only approved drug test kits. There are other issues that you will have to consider while buying a drug test kit.

For example, you must always go for an FDA-approved brand and be very careful in reading the expiration date on the product. Only then can you get a reliable result from it. Always lookout for the date of expiration before buying a drug test kit.

Lastly, you need to make sure that you strictly follow all the company's instructions before purchasing drug test kits.

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