A negative result is quick and a non-negative one is not, and the gap between them is the whole answer. The delay is not the laboratory being slow: it is two additional steps that only happen when the initial screen is not negative, and both of them exist to protect the person being tested. This page explains the sequence and what actually causes a wait.
The normal timeline
A specimen collected today typically reaches the laboratory the next day. An initial immunoassay screen that comes back negative is usually reported within one to two business days of collection. That covers the large majority of workplace tests. Instant point of collection tests give a preliminary negative at the site itself, which is faster still, though any non-negative on an instant device has to go to the laboratory anyway and the clock starts again.
What happens when it is not negative
A non-negative screen is not a positive result and is never reported as one. It goes to confirmatory testing by gas chromatography mass spectrometry or an equivalent method, which identifies the specific substance rather than a class and takes another day or two. If confirmation is positive, the result goes to a Medical Review Officer, a licensed physician who attempts to contact the donor to establish whether there is a legitimate medical explanation such as a valid prescription. That contact is often what takes the time, because it depends on the donor answering the phone.
Why weekends and collection times matter
Almost every step runs on business days. A specimen collected late on a Friday may not reach the laboratory until Monday, be screened Monday or Tuesday, and if it needs confirmation and review, be reported towards the end of that week. If you are quoting a timeline to a hiring manager, count business days from when the specimen reaches the laboratory rather than from when the candidate was told to attend, and add the weekend explicitly rather than hoping.
The other causes of delay
A dilute specimen usually triggers a recollection, which restarts the process. A shy bladder situation, where the donor cannot produce a sufficient specimen, has its own defined procedure with a waiting period. An adulterated or substituted specimen is handled as a refusal under the federal procedure rather than as a result. And an unreachable donor holds the Medical Review Officer stage open, which is why telling candidates to expect a call from a physician's office is a genuinely useful thing to do.
Questions people ask about how long do drug test results take
How long do drug test results usually take?
A negative is commonly reported within one to two business days of collection. Anything that is not negative goes to confirmatory testing and then Medical Review Officer review, which typically adds several days.
Why is my result taking longer than my colleague's?
Almost always because the initial screen was not negative, so it went for confirmation and to a Medical Review Officer. That is the system working, and it exists to catch lawful prescriptions before anything is reported to the employer.
I tested on Friday, when will I know?
Count business days from when the specimen reaches the laboratory, not from collection. A Friday collection often means a Monday arrival, so a straightforward negative lands mid week.
What is the Medical Review Officer call about?
A physician checking whether there is a legitimate medical explanation, such as a valid prescription, before anything is reported. Not answering keeps the result open, so it is worth telling candidates to expect it.