What is MOP on a drug test? MOP is the abbreviation for morphine. On a drug test cup or dip card, the MOP panel screens urine for morphine and closely related opiates such as codeine and heroin, which the body converts to morphine. Most rapid tests print it as MOP/300, meaning a screening cutoff of 300 ng/mL.
MOP is often confused with OPI, the general opiates panel. The two screen for the same family of drugs but are usually set at different cutoffs, and that difference affects how sensitive the test is and how often poppy seeds or prescribed codeine trigger a non-negative result. This guide explains what MOP detects, how it compares with OPI, what it misses and how to read the result.
What Is MOP on a Drug Test?
MOP stands for morphine. The panel uses an antibody designed to recognize morphine, and it also reacts to drugs that are metabolized into morphine or look structurally similar to it.
| Label | Meaning | Common cutoff |
|---|---|---|
| MOP | Morphine panel | 300 ng/mL |
| OPI | Opiates panel (morphine and codeine) | 300 or 2,000 ng/mL |
| OXY | Oxycodone panel (separate test) | 100 ng/mL |
See the complete drug test abbreviations chart for every other code you may find on the same cup.
What Drugs Does the MOP Panel Detect?
- Morphine, including prescription morphine products
- Codeine, which is partly metabolized to morphine
- Heroin, which breaks down to 6-acetylmorphine (6-AM) and then morphine
- Hydrocodone and hydromorphone, which may cross-react, depending on the device and concentration
Heroin itself leaves the body quickly, so a MOP result cannot distinguish heroin use from morphine or codeine use. Laboratories confirm heroin use by finding 6-AM, which has its own federal cutoff of 10 ng/mL (49 CFR §40.85).
What the MOP Panel Does Not Detect
Many commonly misused opioids are synthetic or semi-synthetic and do not react reliably with a morphine antibody. Each of the following needs its own panel:
- Oxycodone and oxymorphone – OXY panel, see the oxycodone drug test strip
- Fentanyl – FEN or FYL panel, see the fentanyl dip strip (FEN/20)
- Methadone – MTD panel, explained in What Is MTD on a Drug Test?
- Buprenorphine – BUP panel
- Tramadol – TRA or TML panel, see does tramadol show up on a drug test
MedlinePlus notes that opioid test results can vary with the medicines a person takes and the method a lab uses, which is why the exact panel list matters when you choose a test.
MOP vs OPI: What Is the Difference?
Both panels target the morphine family. The practical difference is the cutoff:
- MOP/300 and OPI/300 are more sensitive. They catch lower concentrations and are common in clinical, treatment and court programs.
- OPI/2000 matches the federal initial cutoff of 2,000 ng/mL for codeine and morphine. It was raised to that level largely to reduce positives from poppy seeds and is common on workplace-style tests.
Our OPI 300 vs OPI 2000 guide compares the two cutoffs in detail.
Can Poppy Seeds Cause a Positive MOP Test?
Yes, they can. Poppy seeds contain small amounts of morphine and codeine, and eating foods with poppy seeds can raise urine morphine above 300 ng/mL. That is one reason a non-negative MOP result should never be treated as proof of drug use without confirmation and review.
How Long Does Morphine Show Up in Urine?
Morphine and codeine are usually detectable in urine for a few days after use, and longer with heavy or repeated use. The window depends on dose, frequency, metabolism, hydration and the cutoff. A MOP/300 test can detect use for longer than an OPI/2000 test because it reacts to lower concentrations. The ARUP Consult detection windows table lists published ranges, but no window is guaranteed.
Which Tests Include MOP?
| Product | Opiate panel |
|---|---|
| 13 Panel Urine Drug Test with MOP & EtG | MOP/300, plus OXY, MTD, BUP and EtG |
| Opiate Test Strips | OPI/300 single panel |
| Opiate Drug Test Dip Card | OPI/2000 single panel |
| 12 panel drug test cups | OPI/300 or OPI/2000, depending on configuration |
If your program needs both a sensitive morphine screen and coverage of synthetic opioids, choose a cup that lists MOP or OPI together with OXY, MTD, BUP and FEN.
How to Read a MOP Result
- Negative: a control line and a visible test line next to MOP, even if faint.
- Non-negative (preliminary positive): a control line and no test line next to MOP.
- Invalid: no control line. Retest with a new device.
Read within the time stated in the package insert. Our guide to reading a drug test cup shows each result pattern.
Confirming a MOP Result
A rapid MOP result is preliminary. Prescribed codeine or morphine, cough medicines containing codeine and poppy seeds can all produce a non-negative screen. Confirm non-negative results with a laboratory method such as GC-MS or LC-MS/MS, which separates morphine, codeine and 6-AM, and review prescriptions under your program’s procedure. Rapid cups are not used for DOT-regulated testing.
Buying MOP Drug Tests in Bulk
Treatment programs, clinics and courts often order cups with MOP/300 or OPI/300 for sensitive opiate screening. Request a bulk quote with your required panels and cutoffs, or browse all urine drug test cups.
Frequently Asked Questions
What does MOP stand for on a drug test?
MOP stands for morphine. The panel screens urine for morphine and related opiates such as codeine and heroin.
Is MOP the same as OPI on a drug test?
They screen for the same family of drugs. MOP is usually set at 300 ng/mL, while OPI may be set at 300 or 2,000 ng/mL depending on the test.
What is the cutoff for MOP?
Most rapid tests list MOP at 300 ng/mL. Check the package insert for the exact cutoff of your device.
Does MOP detect oxycodone or fentanyl?
Not reliably. Oxycodone needs an OXY panel and fentanyl needs a FEN or FYL panel.
Can poppy seeds cause a positive MOP result?
Yes. Poppy seeds contain morphine and codeine and can raise urine morphine above 300 ng/mL, so non-negative results need laboratory confirmation.
What should happen after a non-negative MOP result?
Treat it as preliminary. Confirm it with GC-MS or LC-MS/MS and review prescriptions and diet before making any decision.
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