What Happens During A LabCorp Drug Test (This Is The Same For Quest & Others)
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LabCorp is the biggest drug testing company in the continental USA, and the one you are most likely to come into contact with.
Quest Diagnostics are the second biggest company and there are other smaller ones, but they have a smaller share of the market.
However, the drug tests these companies do are all the same. The processes are the same, the testing standards are the same. So there are no real differences, and what I’m going to say here applies to any type of commercial drug test.
So what I’m going to do here is tell you everything you need to know about drug testing. I’ll talk specifically about LabCorp, but everything I tell you here can apply to any drug testing company in the USA.
If you live outside the USA, this is still relevant. The processes are the same globally, in fact a lot of drug testing companies around the world are part-owned by American drug testing companies, so the technology and experience are global, not specific to the USA.
The Types Of Drug Testing That LabCorp Specialize In
LabCorp are specialists in all types of drug testing. They do the full range:
- Urine sample drug test
- Hair drug test
- Oral drug test
- Blood drug testing
- Cotinine (nicotine) drug tests
- Other specialist testing
You’ll read a lot about panel drug tests, five panel drug tests being the most basic (although that’s now been replaced by a four panel drug test due to the growing removal of marijuana as a searchable substance).
The truth is panel drug default substances you’ll see listed are a little bit misleading, because when you go to take the drug test you won’t know exactly what’s being tested for. They don’t tell you. That’s because a company can swap out individual panels, or ask for a variation test.
You could also face a variant test because that the company is more interested in not hiring people who have a potential prescription meds problem, for example. So they might swap out a couple of other panels, say PCP and marijuana, to put in more advanced testing for things like benzodiazepines, opiates, and barbiturates.
So don’t think that if somebody says you’re going to LabCorp and you know it’s a five panel drug test that you can just go online and search and find the “cookie-cutter” five substances to know if you will pass or fail.
When Could You Face A Drug Test?
These are the main situations when you could be faced with having to submit a sample for a drug test:
- Pre-employment
- On the job
- Law enforcement
- Courts or probation
- Smoking cessation
- Alcohol problems
- To get insurance
- For a medical procedure
So there is a myriad of reasons why you could face a drug test of some type. But pre-employment drug testing is the most common.
Most companies in the USA do a pre-employment drug test of some type, but far fewer do on the job drug testing.
Also, some federally mandated drug testing is an unavoidable in certain situations. If you work for the government in most ways, or for a company who does federal outsourcing work, then you could face a drug test.
But overwhelmingly it’s pre-employment. It’s a cheap drug test, usually only a five panel one, to make sure that people who are being hired who are struggling with drugs avoid the recruitment process knowing that they are very likely to be screened. Basically, it’s a deterrent to you applying for a job.
Here’s The Procedure For Submitting Your Sample
So let’s say that you have been told that you have to submit a sample, and LabCorp will be processing it.

Here’s what happens when you actually get into that situation.
1. Overwhelmingly, you will be told to report to a specialist center to submit your sample. Don’t get caught out though, as I’ll explain later, this isn’t always the case. You may not get that notice.
2. You’ll get a date and time, usually only 24 hours notice or so, and you’ll have to go along to the location it’s been stated.
3. You don’t usually have any paperwork to take with you. However, you will need to take a government issued ID, to prove that the person submitting the test is actually you.
4. On arrival, you’ll be checked in, and have your ID scrutinized at the same time. They will tell you that you should arrive around 15 minutes before the time of your test. I’ll just mention that in some big city center locations you something called LabCorp express, where you scan your driving license and just wait. There is no prior interaction, it’s just a conveyor belt.
5. When you do meet the person conducting the test, they will usually get you to remove your bag and coat. They may also ask you to remove a hat. In rare circumstances, they may pat you down, but they are not allowed to search you intimately. In my experience though, this is rare, and they don’t usually touch you at all (that’s a bit of a legal minefield for obvious reasons), and only can justify it if they have a strong suspicion.
6. This discussion and preamble will usually take place in the main testing room. This is the place you’re going to submit your sample, or it’s a room next to the place you will. They will go through some paperwork, and ask you some questions about anything you’ve taken, in order to highlight potential false positive result situations.
7. You’ll then either go behind a screen in the same room, or into a separate room to submit your sample. Note that most drug tests are unsupervised, you will have to be notified in advance if it supervised, and it’s usually only for very specific or unusual circumstances. If it supervised, they can’t look directly at you, but they can be in the room to try and head off the submitting of fake samples.
8. You’ll then pee into the container they have given you. It will have a temperature strip down the side, and a minimum fill line.
9. When you’re finished you simply hand it over to the assistant. They may test the temperature and do some preliminary recording while you’re still there, but usually they will just say thank you and you will leave immediately.
What Happens To The Sample After You Submit It?
After you submit the sample, it has to be tested to make sure it’s within the correct temperature range (if it’s a urine sample drug test). This has to be done within four minutes of handing over, and if it’s between 90°F 100°F then it’s a legal sample.

Whatever type of sample it is, it will then go through basic screening. For hair, blood, and saliva, it goes straight onto the panel drug test. For urine sample testing, they may do some additional validity checks, including a visual scrutiny.
Whatever happens before, it will then be tested against panels, or on digital equipment. This will give them the results. Any metabolite presence above the cut-off level for the test are recorded.
If there is doubt about the test, or you test positive, then it will go to a full level III gas chromatography – mass spectrometry analysis. This is more expensive though, and isn’t often done unless there is a real problem.
Unless is a problem, your drug test results will go to the person who commissioned the test within about 24 hours, or 48 hours if they are busy. If you haven’t heard anything after two days, then either they are exceptionally busy, or you could be facing increased scrutiny.
Don’t Think That You Have To Go To A Specialist Centre To Submit A Sample (Don’t Get Caught Out)
Remember that samples do not have to be scrutinized immediately, and can be often be taken anywhere.
Hair samples can be taken away to be scrutinized somewhere else, although they have to be collected by a specialist. So these are usually still done by reporting to a test center, or incredibly rarely, you could have an employee of the drug company at another location collecting the sample to take away.

Oral swab drug testing can be done by anyone with minimal training. So don’t have to go to a test center to suddenly be faced with a mouth drug test. Most oral swab drug testing is not done at specialist test centers, it’s administered by trained people from the company, or the drug test company, at other locations.
Blood drug testing is incredibly rare, and unless you are in a location where it can be done by specialist then it won’t happen. Going for a job interview? Don’t worry about blood drug testing.
I’ll finish here by saying that recruitment days are especially dangerous. That’s where they churn a lot of interviews at once. That is the most likely situation where a representative from a drug testing company is likely to be present and can administer a surprise drug test with no notice.