MOP on a drug test means morphine, and with it the opiates panel. On a urine test cup or a result, those three letters mark the strip that screens for the morphine family: morphine, codeine and heroin. Some cups print the same panel as OPI, and a Testr report prints it as MOR. Below: what the MOP line can tell you, how prescriptions and poppy seeds affect it, where other opioids show, and what a laboratory report lists instead.
MOP stands for morphine and the opiates panel
Opiates are natural opioids such as morphine and codeine, along with heroin, which the body turns into morphine. Some prescription pain and cough medicines fall in the same group.
Test strips carry short codes instead of full drug names, and this panel has three in common use. MOP and MOR point to morphine, the compound the strip is built around; OPI points to the opiates group. Whichever spelling a cup uses, the panel screens for the same substances. A Testr report prints it as MOR (Morphine / Opiates), one of 14 drug panels, and the rest are covered in every drug test abbreviation, decoded.
MOP works as a group screen. It responds to the morphine family as a whole, so a presumptive positive line does not say which opiate was there, where it came from, or how much.
What the MOP line actually reports
A certified collector reads the 14-panel rapid urine screen on site. On a Testr screen, a specimen reads presumptive positive on the opiates line at or above the 300 ng/mL cutoff; otherwise the line reads negative. No measured level is given.
Below the cutoff the panel reads negative even when a trace is present, so a negative is not proof that no opiate was ever taken. The panel's published window: usually detectable in urine for 2-3 days after use, at a 300 ng/mL screening cutoff. That range is typical rather than a guarantee, since how much was taken, how often, body weight and hydration all move it. The opiates page covers how long opiates stay in your system alongside codeine, heroin and poppy seeds.
The cassette's creatinine, oxidant and pH checks are for specimen validity and say nothing about opiates. The difference between negative, presumptive positive and laboratory-confirmed is laid out in how to read a Testr drug test result.
OPI300, OPI2000 and the number beside the code
MOP is a label, not a standard. The number printed beside it is the cutoff, and it is not the same on every cup. Some cups print OPI300 and some print OPI2000: the same opiates panel, read at 300 ng/mL or at 2,000 ng/mL.
That gap matters. One specimen can read presumptive positive on a 300 cup and negative on a 2,000 cup, and neither cup is wrong. The code alone does not say how sensitive the test was, so the number beside it is part of the result. A Testr cassette reads opiates at 300 ng/mL.
Prescriptions, poppy seeds and a positive MOP
Codeine or morphine prescriptions, and even poppy seeds, can cause a positive on the opiates panel. The strip reacts to the morphine family, and a codeine cough medicine or a morphine pain prescription taken exactly as directed is still in that family. The on-site read cannot tell a prescription, poppy seeds and heroin apart. The line reads presumptive positive or negative and nothing more.
Valid prescriptions are accounted for at the laboratory stage: every laboratory report goes to a Medical Review Officer (MRO), a physician who reviews laboratory-confirmed results and accounts for valid prescriptions before the report is released. Without laboratory confirmation, the visit gives a screening result only.
The other 13 panels are covered one by one in what can cause a false positive, panel by panel.
Other opioids and where each one shows
The opiates strip is built around morphine. Several opioids people expect it to catch are different molecules, and on a Testr cassette each one has a line of its own:
Oxycodone (OXY). The opioid in OxyContin and Percocet. Usually detectable in urine for 2-4 days after the last dose, at a 100 ng/mL screening cutoff. See the oxycodone drug test.
Fentanyl (FEN, also printed FYL). Usually detectable in urine for 1-3 days after use, at a 10 ng/mL screening cutoff. Does a 14-panel drug test detect fentanyl covers what that strip can and cannot catch.
Buprenorphine (BUP). The medication in Suboxone and Subutex. Usually detectable in urine for 3-7 days after the last dose, at a 10 ng/mL screening cutoff. A person taking Suboxone can read negative on the opiates panel and presumptive positive on BUP in the same specimen; BUP on a drug test explains why.
Methadone (MTD). Usually detectable in urine for 3-7 days, sometimes longer with regular dosing, at a 300 ng/mL screening cutoff. See the methadone drug test.
Tramadol has no line of its own on the cassette. It is an opioid, but neither the opiates panel nor the oxycodone panel is built around it, so a negative on either line is not a result for tramadol. It is, however, one of a few common medicines documented to cross-react on PCP screens. The laboratory menu carries it as its own class, covered in lab-only drug test results.
Hydrocodone (Vicodin, Norco) and hydromorphone (Dilaudid) are a separate case. They have no panel of their own on the cassette, and Testr does not claim the MOR panel reads them at its 300 ng/mL cutoff, so a negative MOR line is not a result for either. The laboratory menu lists both by name, below. Oxymorphone, also on the laboratory list, is a breakdown product of oxycodone and a prescription opioid in its own right.
This is why the panel count matters. A standard 5-panel drug test cup carries an opiates line but none of OXY, FEN, BUP or MTD, and on a cup without those lines, a MOP result is not a result for any of them.
What the laboratory reports for opiates
With laboratory confirmation, the sealed specimen travels under chain of custody to a CAP-accredited laboratory, which confirms by LC-MS/MS. The laboratory menu has no single line for the group. Its opiates class lists five compounds by name, each with a 50 ng/mL cutoff:
Codeine
Hydrocodone
Hydromorphone
Morphine
Oxymorphone
Separately, the menu lists 6-acetylmorphine (6-MAM), the metabolite specific to heroin, at 10 ng/mL. 6-MAM has no line on the rapid cassette, though some other cups print one.
The laboratory reports measured levels in about 72 hours, and every laboratory report goes to the MRO before it is released. The two sets of numbers are not comparable. The 300 ng/mL beside MOR applies to the group read as one line, while each laboratory cutoff applies to a single named compound. The full laboratory menu covers 81 substances.
An At-Home Rapid Test can add laboratory confirmation from the app within 2 hours of collection, while the specimen is still viable. The 2-hour upgrade window walks through that choice and its timing.
Getting an opiates screen in Los Angeles
Every Testr visit reads all 14 panels, so the opiates line comes back in the same result as OXY, FEN, BUP and MTD. A certified collector comes to a home or workplace within 20 miles of Century City, in plain clothes and an unmarked vehicle, and verifies identity at the door with a private PIN. The specimen's temperature is checked, and it is sealed under a chain-of-custody code.
Parents, therapists and employers can book a visit for someone else. When the person tested is a minor, a parent or legal guardian is present for the whole visit and signs consent. See Testr for parents and Testr for professionals.
Results go only to the account holder, or to a named third party with written consent. Testr is non-DOT and tests urine only. What a workplace policy requires is a question for employment counsel, and if a result is meant for a court, ask your attorney or the court what they accept.
Questions people ask
What does MOP stand for on a drug test?
Morphine, and with it the opiates panel: morphine, codeine and heroin. Some cups print the same panel as OPI. A Testr report prints it as MOR (Morphine / Opiates).
Is MOP the same as OPI?
Yes. Both name the opiates panel. The cutoff beside the code can differ, though: OPI2000 reads at 2,000 ng/mL, and a Testr screen reads at 300 ng/mL.
Does oxycodone show up as MOP?
MOP is not the panel built for it. Oxycodone has its own OXY panel on a Testr screen, and oxycodone is usually detectable in urine for 2-4 days after the last dose, at a 100 ng/mL screening cutoff.
Does hydrocodone show up as MOP?
Testr does not claim the MOR panel reads hydrocodone at its 300 ng/mL cutoff, and hydrocodone has no panel of its own on the 14-panel screen, so a negative MOR line is not a result for it. The laboratory confirmation menu lists hydrocodone at 50 ng/mL, which makes Vicodin or Norco a laboratory question.
Can poppy seeds make MOP positive?
Yes. Poppy seeds, like codeine or morphine prescriptions, can cause a positive on the opiates panel. Poppy seeds carry traces of morphine and codeine, so a presumptive positive MOR line points to the morphine family, not to where it came from.
Does a positive MOP mean heroin?
Not on its own. The strip reads the morphine family as one group, so a codeine or morphine prescription or poppy seeds can make it read presumptive positive too. The laboratory menu lists 6-MAM, the metabolite specific to heroin, as a separate compound.
How long do opiates stay in urine?
On a Testr screen, opiates are usually detectable in urine for 2-3 days after use, at a 300 ng/mL screening cutoff.
Does MOP catch fentanyl or Suboxone?
Neither is its target. On a Testr screen, fentanyl is read on the FEN panel at a 10 ng/mL cutoff, and buprenorphine, the medication in Suboxone, on the BUP panel at a 10 ng/mL cutoff.
To have all 14 panels read at your door, opiates included, choose a 30-minute window between 7 AM and 7 PM, seven days a week, in the Testr iOS app or at testrla.com/book. The earliest window can start in as little as 3 hours. Book a visit.