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Re: Candidates – What to Know About Pre-Employment Drug Tests

Female holding a glass of water.

Pre-employment drug tests are typically conducted at the tail-end of the hiring process, so it is no surprise that they can cause a bit of anxiety. Standing between the candidate and their new position often lie the results of their drug screen.

While Peopletrail has a collection site network of well over 10,000 clinics across the country, our own offices also include a collection facility where candidates can come to complete their drug screen. While assisting candidates, our staff is made aware of some common concerns, questions, and anxieties.

This article addresses some of these candidate questions, providing helpful insights into what to expect before collection and while results are pending.

1. Urine Tests Are Still the Most Common (Come Prepared)

Overall, urine testing is still the most common pre-employment drug screening method. 

While slightly more invasive than other methods, urine testing ensures a stable metabolite lifespan giving a fair amount of insight into recent and past substance use.

Check out this article for more information on substance detectability by screening method.

Of course, a urine sample is needed for a urine drug test, meaning you will need to come ready to provide the sample (only about 30-60 mL of fluid). We recommend drinking a glass of water 30 minutes before arriving at your collection appointment. Just make sure not to drink too much water. 

If too much water is consumed before a sample collection, the test may render as ‘dilute,’ and a re-test will be requested.

2. Schedule Ahead With the Collection Facility

While most clinics in our network allow walk-in collections, we highly recommend you make an appointment.

Depending on the location and time of day, walk-ins may experience long waits that can cause frustration and interfere with their ability to provide a proper sample.

Once your collection site is determined, give them a quick call and arrange a visit.

3. You May Be Contacted Before Drug Test Completion

The Medical Review Officer (MRO) process will be initiated for all lab-positive samples. The Medical Review Officer is a physician that works with candidates to verify any prescriptions that may have influenced the drug test results.

Certain pain medications, ADHD medication, antidepressants, or other legally-prescribed substances may trigger a panel on the drug screen. Whenever a positive sample returns from the lab, the MRO will contact the candidate directly and ask about their medication history/schedule. If the MRO is able to verify medications, they will change positive results to negative before reporting to the employer.

The employer will not be made aware of details regarding the medications discussed.

The MRO process can delay the drug test and increase time to hire if candidates are not responsive to MRO outreach. If you are on any medications going into your drug test, be sure to keep this process in mind and look out for a call from the MRO.

4. All Initial Positives Are Further Tested In a Lab

At times, instant tests are administered at the collection facility. These instant tests are good at quickly determining negative results but are less effective in determining reliable positive results. For this reason, instant test positive samples will be sent to a laboratory for further testing.

Because of this, false positive results are extremely rare. All positive results are tested in a lab setting and reviewed carefully by a physician before they are reported.


The drug test process is simple and straightforward. If you have no history of substance abuse/illicit use, there is no need to be nervous about your results. False positives are incredibly rare, and results can be challenged in the very unlikely event they do happen.

In addition, if you are on prescription medication that triggers a positive result, you can verify any and all prescriptions with the Medical Review Officer, who will contact you. Once such authorized substance use is confirmed, the results will be changed before they are reported, and the employer will not be informed of the details.

All you need to do is schedule an appointment with the clinic we provide you, drink a glass of water before you leave, arrive 10 minutes early, and keep a passive eye out for a call from the MRO. We’ll have the results back in no time.

For more information about pre-employment drug testing, visit us online.

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