How to Dispute a False Positive Drug Test

March 23, 2022
Checkr Editor

Editor’s note: Nothing in Checkr’s Blog should be construed as legal advice, guidance, or counsel. Companies should consult their own legal counsel about their compliance responsibilities under the FCRA and applicable state and local laws. Checkr expressly disclaims any warranties or responsibility or damages associated with or arising out of information provided.

Employee drug testing is far less prevalent than people believe. Just 1.47% of job postings mentioned drug testing as a requirement of employment. Modern drug testing mainly focuses on several key industries, such as healthcare, automotive, and private security.

Did you fail a drug test and believe that you fell victim to a false positive? Plenty of candidates have found themselves in this difficult situation.

So, can you fight a positive drug test? Figuring out how to dispute a false positive drug test is not always straightforward.

What can drug tests detect?

Modern technology enables drug tests to detect a variety of substances. Employers may order custom tests to detect any substance of concern.

Due to the easing of marijuana laws in states like Nevada and Maine, lawmakers have passed bills preventing employers from judging applicants based on positive marijuana test results, with a few exceptions for specific roles and responsibilities.  Municipalities like New York City also have this rule in place with similar exceptions.

There are two common types of drug tests employed within the U.S.

  • 5-Panel Drug Tests - Sampling for amphetamines, cocaine, marijuana, PCP, and opiates.
  • 10-Panel Drug Tests - Detects all of the above plus barbiturates, benzodiazepines, methadone, methaqualone, and propoxyphene.

Employers may also order specific panel tests for substances like Oxycodone and Oxycontin. Customized panel tests may be employed within industries that have high rates of abuse of certain substances.

Drug testing is effective at uncovering the presence of prohibited substances. However, no commercially available drug test is 100% accurate.

What can cause a false positive drug test?

To understand what can give you a false positive on a drug test, you need to know how a panel test works.

Panel tests use paper strips containing antibodies. In much the same way as a home pregnancy test, the strip will change color if a substance is detected.

These tests are designed to be quick, cost-effective, and convenient. The problem is that false positives results can occur.

Understanding what causes false positive drug test results can help you dispute a false positive.


The first step for how to fight a positive drug test is to assess which medications you took. There are countless over-the-counter (OTC) medications and prescription drugs containing substances that could lead to a false positive.

Some of the most common painkillers known to cause false positives include Advil, Aleve, and Motrin. Even nasal decongestants and cough remedies, such as Sudafed and Delsym, have triggered false positive results.

You should also be aware that certain antidepressants like Zoloft and Prozac, along with sleeping pills like Tylenol can cause a false positive.

Anyone taking OTC or prescription medications should raise the matter immediately after a false positive.


Medications are not the only way to trigger a false positive. Several substances in your pantry or bathroom cabinets could also complicate an accurate result on a panel test.

Here’s a brief rundown of some common substances that could cause issues:

  • Cannabidiol (CBD)
  • Mouthwash
  • Hand sanitizer
  • Vitamin B supplements

There’s a reason why you’re advised to avoid eating or drinking anything at least 30-60 minutes before submitting to an employee drug test. Even the slightest presence of a foreign substance could lead to you testing positive.


Foods can also trigger a positive drug test. Poppy seeds are notorious for causing people to test positive for opiates, specifically morphine. You may even be explicitly advised to avoid any foods containing poppy seeds, such as granola bars, for at least 24 hours.

Other foods that could be problematic include:

  • Pizza
  • Durian
  • Coca tea
  • Hemp seeds
  • Tonic water

The foods on this list might seem harmless, but can still cause a positive test result. For example, tonic water contains quinine, a substance that is sometimes mixed with heroin.

How to dispute a false positive drug test

Wondering, “What happens if I get a false positive on a drug test?” The answer is to tackle the issue head-on. You know the results are not right, and there’s no reason to let a false positive prevent you from getting your dream job.

First, seek independent support. Checkr can only offer basic guidance on the steps you need to follow when faced with how to fight a false positive drug test.

Consult a specialist who can represent and support you through the process.

Step one: be transparent

If you use prescription medications or regularly eat foods like poppy seeds, notify the person testing you so they can take this into account. Bring along documentation regarding prescription medications issued by your doctor.

In the event you do return a false positive, the information provided could serve as grounds to allow a further panel test. Remember, the test provider has no idea who you are. Provide as much documentation as possible to help the test provider interpret the results.

If you are already wondering what to do if you have a false positive drug test, this advice can come in handy as you prepare for the next steps.

Step two: consult a professional

Start with self-reflection. Consider everything you consumed in the hours and days prior to the test. Think about what could be to blame.

In the case of medication, you should seek professional advice from your doctor or pharmacist. Ask them if any of the ingredients inside your medication could have caused a positive test result.

If the answer is yes, most medical professionals will be happy to provide you with an official letter noting the medication you are taking that you can present to an employer.

You may also want to reach out to the lab to ask about next steps if you believe that your test result is inaccurate.

Step three: opt for a re-test

Re-tests are the next step. Many employers understand these panel tests may result in false positives. Simply ask if you can take another test. Many will have no problems accommodating your request.

It helps to present evidence as to why you tested positive the first time. As already mentioned, a letter from a doctor or pharmacist regarding a prescription medication will help.

Unionized worksites often have rules and regulations in place that allow for an immediate re-test without requiring any evidence.

Does an employer need to accommodate your disagreement with the test result?

It largely depends on the employer. Many states operate under a work-at-will policy. In this case, employers have flexibility to hire and fire as long as they do so legally.

Job candidates need to act quickly if they yield a false positive, as employers are not required to keep the job on hold. They may decide to offer the job to another candidate.

False positive drug testing FAQs

Now that you know how to dispute a positive drug test, you may have some questions regarding false positives and how they relate to your employment prospects.

What causes a positive urine screening?

Urine screenings tend to yield false positives more often than other analyses, most commonly when the screenee uses poppy seeds, CBD, and certain OTC and prescription medications.

This is because many of the ingredients from the list above have a lot in common with the drugs the testing provider needs to detect. For example, CBD is derived from one of two types of cannabis plants: marijuana and hemp. Therefore, the use of CBD may lead to a marijuana false positive.

Can an employer rescind a job offer due to a false positive?

Generally, there’s nothing to stop an employer from rescinding a job offer as a result of a false positive. They are not generally required to allow you to fight your case or opt for a re-test.


Knowing how to dispute a false positive drug test is a useful skill to have if you find yourself in this situation. Employers also need to be aware of the likelihood of false positives occurring via panel tests.

Drug testing may not be as common today, but background checks remain a core aspect of ensuring that candidates have the education, experience, and skills necessary for the job.

Save time and avoid hassle on background checks. Contact Checkr to learn more about the background check process and make your hiring decision sooner.

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