At-Home Drug Tests: What They Are and How They Work

At-home drug tests are urine or saliva tests that can identify if illegal or prescriptions drugs are present in your body.

These tests are an alternative to going in person to a laboratory or other healthcare organization to test for the presence of drugs.

Some of these at-home drug tests are also designed to detect multiple substances from a single sample through a two-step process. The first step is the actual at-home sample collection and the second step is sending that sample to a laboratory for definitive testing confirmation.

But with the benefits and convenience of these tests also come some drawbacks. Here’s a closer look at what these tests involve, how accurate they are, the best time to take an at-home drug test, and what you can hope to learn from the results.

At-home drug tests are typically urine tests or saliva tests used to identify the presence of certain drugs. These may be illegal drugs, medications that have been prescribed to a person, or medications that a person is using in an illegal fashion. Examples of drugs that an at-home drug test can detect include:

barbiturates
benzodiazepines
cocaine
ecstasy
marijuana
methadone
methamphetamines
oxycodone
prescription painkillers
tricyclic antidepressants

In a healthcare setting, drug tests may include urine, hair, saliva, or blood samples. However, at-home drug tests are typically urine or saliva because, in some cases, they can show results instantly or within just a few minutes.

At-home tests also offer the benefit of using simple or basic equipment and testing steps that can be performed with little training or prior experience.

You can purchase an at-home drug test that detect the presence of just one drug (such as cocaine, methamphetamines, or THC, the active component present in marijuana) or multiple drugs from one sample.

When buying an at-home test, read the labels carefully to ensure you’re buying the correct one for your testing needs.

At-home urine drug tests most commonly work by urinating in a collection cup and inserting a test strip or cassette to test the urine. The test strip will interact with the urine and turn a specific color to indicate the presence of particular drugs.

Most drugs are lipid-soluble , which means the liver breaks them down and transfers some of the components to the kidneys, where the kidneys then release the waste components via your urine. A urine drug test contains compounds that react with drug waste products and causes the test strip to change color after detecting them.

A saliva-based drug test is similar. It involves swabbing the inside of your cheek and inserting the swab into a test collection device or placing the saliva sample directly onto a special test strip. If illegal substances are present in your saliva, the test strip’s components will react with the drug — or common components of the drug — and change colors.

While reading or reaction times for each test type can vary, most tests will show results within 5 minutes of coming in contact with urine or saliva.

Pros

They’re generally easy to use with no needle sticks required.
They can be performed at home.
Urine and saliva tests can usually provide results within hours after a person has used a substance.
Tests are usually relatively inexpensive (less than $20 a test).

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Cons

It may require direct observation for sample collection to ensure accuracy.
Some people may experience “shy bladder” syndrome and have difficulty producing a urine sample at the time of testing.
Recently eating or drinking can affect the accuracy of some saliva tests.
Insurance doesn’t usually cover the costs of these tests.

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If you visit a pharmacy aisle or shop online for an at-home drug test, it’s easy to get overwhelmed with all of the options that are available. Here are some key features to look for to ensure you get the most effective test for you or a loved one.

Substances tested

Some at-home drug tests will identify a single substance, and some tests can even detect around 14 or more substances at one time. When buying a test, make sure that it will provide an answer for the substance you’re testing for and in an acceptable window of time.

Ease of use

While each at-home drug test will have additional step-by-step instructions for administering the test, you can usually tell from reading a box’s packaging how easy or difficult the instructions will be to follow.

If the test’s steps seem too difficult to follow or you’re concerned that you won’t be able to accurately collect the sample, you may wish to choose another test or test type.

It may also be worth reading customer reviews for the at-home test you’re considering. User reviews can be a good way to learn how difficult a test is on average.

Test type

As a general rule, test kits for saliva can’t detect as many drugs as a urine test can. If you’re considering testing for a wide variety of drugs, you may wish to opt for a urine test.

Some at-home drug tests have optional features too. If you wish to have these features included in your test, the cost will likely be higher than a traditional test kit.

Laboratory confirmation

If you want to make sure your results are as accurate as possible, a laboratory confirmation option may be more advantageous than a single-step test or a saliva test that doesn’t typically offer a laboratory option.

This consideration will often depend on the purpose for the drug test. Additionally, your test results will take longer when you consider the added shipping and travel time.

When purchasing at-home drug test kits, you should look for tests that are authorized for use in the United States and have been cleared by the Food and Drug Administration (FDA).

The FDA evaluates these tests based on their accuracy as well as how easy the package insert instructions are to follow. This helps to ensure a more accurate test for users. The FDA also maintains a searchable list of FDA-cleared at-home tests.

At-home drug tests can run the risk of being inaccurate due to human error or incorrectly collecting the sample to perform the test. For example, you must:

Perform the test exactly as the directions recommend.
Collect and store your urine or saliva as recommended.
Consider any medications you’re currently taking that could skew the test results. For example, healthcare professionals may prescribe amphetamines (such as Adderall) to treat attention deficit hyperactivity disorder (ADHD). However, taking these medications would cause a person to test positive for amphetamines because the at-home tests cannot detect the key differences between the two.

If one or more of these steps are not completed correctly, it could cause a false positive or a false negative. This could have potentially negative repercussions if results show a drug is present in someone’s system that isn’t really there.

As a general rule, your insurance policy won’t cover at-home drug tests unless a healthcare professional writes a letter of medical necessity. This letter explains why you need to purchase drug tests either on a one-time or routine basis for a medical reason.

FSA and HSA eligibility

If you do have a letter of medical necessity for at-home drug tests, you may be able to purchase the test using funds from your flexible spending account (FSA) or your health savings account (HSA). However, it’s worthwhile to talk to the company that manages your benefits before you purchase the tests to make sure your FSA or HSA plan will cover the costs.

At-home drug tests have a number of potential uses. These include:

Clinical: Sometimes you may be asked to provide a drug test as proof of sobriety or continued sobriety. An insurance company may also ask you to complete a drug test to obtain insurance coverage for a life insurance policy.
Employment: Some people must complete a pre-employment drug test or participate in routine or randomized drug testing as part of their employment. Ask your employer to ensure they will accept an at-home drug test as proof you are drug-free.
Legal: While the situation may vary, courts don’t usually accept at-home drug tests as legal proof of being drug-free. If you wish to use an at-home drug test for any legal matters, make sure you receive approval first. Law enforcement officers may also use at-home drug tests in the field to test individuals for the presence of illegal substances.
Personal: If you’re worried that you may test positive for a drug or taken a drug without your knowledge, you may wish to use an at-home drug test. Some families (such as a parent) may also use at-home drug tests to test for the presence of illegal drugs.

Remember that an at-home drug test represents a moment in time. Even if a person tests negative for a drug, it’s possible they could test positive at a later time. If you’re testing a loved one, you may need to perform repeated tests to make sure you’re getting accurate results.

How accurate are at-home drug tests?

At-home drug tests can detect the presence of certain drugs in your urine or saliva, but they aren’t specific about the level of those drugs in your system.

Additionally, some complex “designer” drugs that are synthetic and/or lab-made, may not be detected by an at-home urine test because the formulations of these drugs may be constantly changing.

No at-home drug test is 100% accurate. You can have both false positives or false negatives. For this reason, using more than one test at different times of the day or week can usually help if you’re getting a positive test result for you or a loved one.

How long will drugs show in a urine test?

How long a drug will or won’t show in a urine test depends on the drug type you’re testing for.

For example, marijuana will typically cause you to test positive within 1 to 3 hours after use and then for up to 7 days afterward.

However, THC, which is found in marijuana, can have a longer half-life of elimination and can be present for several weeks in the urine of frequent or heavy marijuana users. Taking amphetamines, such as methamphetamines, can cause you to test positive within 4 to 6 hours and for up to 3 days after use.

Saliva tests don’t tend to have as long of an acceptable testing window. A saliva test can detect marijuana for up to 24 hours after using it. Substances like cocaine, morphine, or heroin can be present up to 36 hours after taking them. One of the longest windows of time where these drugs can be detectable is in hair for up to 90 days .

How long can at-home drug tests detect drugs?

At-home drug tests have a shelf life. This means that if you got your test a few years ago, it probably won’t effectively detect the presence of drugs anymore.

The shelf life will depend on the manufacturer’s guidelines and can vary from test to test. Store your tests at room temperature to help extend their shelf life — exposure to extreme temperatures could potentially affect the accuracy of the results.

At-home drug tests are a mostly accurate method for detecting the presence of illegal substances or prescription drugs. But factors like user error and some designer drugs can skew the results.

Following the package instructions as carefully as possible can ensure the most effective result. If needed, repeat the test on different days or times of the day to help rule out any false positives or negatives.

Last medically reviewed on March 23, 2023