Are Drug Tests Accurate? – Frequently Asked Question

The drugs you did last night, at the weekend party, or even on last New Year’s eve – they can all be in your system, be it your blood, urine, saliva, or even hair, waiting to be detected either by the government, your employer, or in the worst case, your parents when they use drug testing kits for home use. That’s what makes drug testing a nightmare for any user.

What are drug tests used for?

Drug tests are used to detect the use of illicit drugs in job applicants, athletes, criminal offenders, participants of drug rehabilitation programs, and others. If illicit drugs are detected, the person usually endures some sort of consequence.

Knowledge is power. The more you learn about drug tests, the better your chances are to beat it, so let’s get started.

Only a few decades ago, the human body was shielded from the outside world just like a well-built fortress, and detecting what’s inside it was nearly impossible. Unfortunately, recent advances in science have given birth to sophisticated drug testing, a multi-billion dollar industry that exists just to shame you by revealing your wrongdoings that you thought will never be known by others.

Types of Drug Tests

There is a wide variety of drug tests which can be divided into two major categories: doing drug testing at home and professional drug testing done by a qualified expert, usually in a sophisticated facility.

At Home

Several drug tests, such as urine test or saliva/oral fluid tests can be easily done at home. All you need to do is buy one of the home drug test kits available as over-the-counter strips, collect a sample of urine or saliva, dip the strip in the urine/saliva for the specified amount of time, and view the reading. These strips are available online as well as in stores, are fairly easy to use, and come with detailed directions. However, results from cheap drug test kits can usually be misleading and incorrect. Even if you use a high-quality kit, there are several external factors that can impact the results of the test, unless you do a lot of research, have some working knowledge of testing, and are very careful in your approach.

Are home drug testing kits accurate?

Home drug testing kits can provide accurate results if they are done very carefully. However, home drug testing kits, especially cheap ones, have the potential to be misleading or inaccurate considering there are a number of external factors that can affect the test’s results that someone doing the test at home may not know about. They are also not accepted when it comes to Department of Transportation Drug Testing or Pre-Employment drug testing. A drug test must be performed at a certified drug testing facility lab like Smart Drug Testing.


Professionally conducted drug tests are more accurate, offer a deeper insight, and are more expensive. There are different types of professional drug tests including urinalysis (urine test), swab (saliva test), blood test, hair follicle test and so on.


To realize the popularity of the urinalysis, consider this fact: 90% of the 55 million drug tests performed last year were urine tests. It’s called the gold standard of the drug-test industry – no pun intended. Because most part of the drug is already metabolized, the urine test, instead of detecting illicit parent drugs, tries to detect the presence of non-psychoactive drug metabolites. For example, marijuana’s primary metabolite is THC-COOH which is fat soluble and can be detected in urine for up to two weeks. Urine testing, despite its popularity, is the easiest of all the tests to beat using a variety of tricks.

Blood Test

It’s the most invasive and the most accurate form of testing. Unlike urine test, blood test actually detects the presence of parent drugs and not their metabolites because most drugs, such as nicotine, marijuana, are instantly absorbed by your bloodstream and are easily detectable. Since these are the most expensive type of tests, they are less common and are only administered if a lot of money or law is on the line. Also, most drugs don’t stay in your bloodstream for too long. For example, marijuana becomes undetectable after a few hours of use, but in chronic users, it can stay detectable for more than 24 hours.


Saliva testing for drugs is administered to detect the presence of parent drugs. It’s less invasive than the urine test and less expensive than the blood test, however, its accuracy can be questionable if not done right. For instance, very little amounts of THC from marijuana or nicotine from tobacco is released into saliva. So, the detection window for the drugs is very small i.e. within just a few hours of use. However, some drugs enter oral fluid through diffusion from the bloodstream and can be detectable for a little longer. The ease of use and low cost are the key factors helping saliva test gain popularity.

Hair Follicle

Mostly is currently used for research purposes, hair follicle testing is very hard to beat but can be the least accurate approach for several reasons. The test tries to detect the presence of drug metabolites diffused from the bloodstream into the follicle. The hair test can offer data like no other, such as detecting drug as well as patterns of use. For example, if you used a drug, then abstained for a certain amount of time, and then used it again, the test will reveal all the data.

However, contamination from the surroundings is the major issue for hair testing. Even the smallest amount of a powder or smoke can get stuck into hair and could result in a false-positive test. While some renowned laboratories try to dismiss this claim but many experts believe that as compared to white hair, dark hair is a true magnet for contaminants making Asians, Africans, and Latinos more prone to false-positive results.

What is the most common type of drug test?

The most common type of drug test is a urine analysis. Of 55 million drug tests that were administered in 2015, 90 percent of them were urine analyses. A urine analysis is much cheaper than other tests and tends to have a longer detection time than if the test were conducted with blood or saliva samples.

Accuracy and Reliability of Drug Tests

Drug testing can be accurate if done properly, but can be beaten very easily and the results can be extremely misleading. The accuracy depends on how strictly the collection was done, if the collection was done inside the detection window of the drug, and whether it was random drug testing or the subject had prior knowledge of the testing.

The results of drug testing depend on how strictly the specimen was collected. For instance, when urine is collected, its temperature should be between 96 and 99 degrees. Otherwise, the subject might have contaminated their urine and the results might not be correct.

Secondly, it’s important to remember that drugs can have different detection window depending on the test. Specimen collected too soon or too late will not offer accurate results. For example, most drugs can appear in blood stream very quickly but also leave the system shortly after the use. Likewise, oral fluid testing is more accurate during the early moments of drug use. On the other hand, drugs take a while to metabolize and appear in the urine.

Randomly choosing subjects and not giving them knowledge of the test in advance doesn’t leave them time to abstain from the drug or use any tricks to beat the test.

Applications of Drug Testing

So what are the major applications of drug testing? Although drug testing is on a decline in the States, because employers have started to realize that there is little benefit for a lot of hassle. The government, as well as drug-test industry, promised the organizations that proper drug screening will ensure safety and will enhance productivity, but this really hasn’t happened. The impact can be seen in the rate of testing dropping down from 81% in 1996 to 62% in 2004. The biggest drug tester in the US is the federal government itself, subjecting 400,000 employees. However, there are several other scenarios where the application of drug testing can occur:

  • Drug testing by employers to detect the use of illicit drugs
  • Screening of athletes and sportsmen to detect any illicit performance enhancing drugs
  • Testing by police officer, for instance, testing for illicit substances in people who seem to be DUI
  • Insurance companies doing drug testing before they let an individual purchase a plan
  • Testing as a result of court order, usually in cases of child custody or after allegations of date rape drug abuse
  • Testing by a health professional to figure out causes of a disease the individual is suffering from
  • Drug test to monitor a person who is abstinent and has joined a support program

We can schedule your drug test in one of our local drug testing centers with just one phone call. We have testing centers nationwide with more than 10,000 locations. We are known as #1 drug testing centers in the nation. Our professional team of drug test consultants are available to help, so for more information or to schedule your drug screening, call (800) 977-8664.