How long are opiates (heroin, morphine, codeine) detectable?

After single use, opiates are usually detectable for 1 to 3 days in urine, a few hours to about a day in blood and saliva, and up to about 90 days in hair. Heroin use itself is only briefly detectable through the specific breakdown product 6-MAM. Below you can read what a certified lab actually measures, per substance and per test material.

We notice that opiates cause a lot of confusion, because the group covers several substances that flow into one another. Codeine is partly converted to morphine in the body, and heroin is broken down very quickly into morphine via an intermediate step. A lab test therefore often measures morphine, while the source was something else. That difference determines what a result really says.

How long do opiates stay detectable per test material?

The guide values below apply to single to occasional use. With frequent use, a high dose or a slow metabolism the times increase. These are ranges, not guarantees.

The short window of 6-MAM is no coincidence. This substance, in full 6-monoacetylmorphine, only forms from heroin and disappears within a few hours. If 6-MAM is found, that points specifically to heroin use. If only morphine is found, the source could just as easily be a morphine-containing medicine or even poppy seed.

Why a positive opiate test does not always mean heroin

An opiate screening reacts to the whole group at once. That is set deliberately wide, so it misses little. The downside is that a first positive result does not tell you which substance caused it. Poppy seed on a roll, for example, can release enough morphine and codeine to trigger a sensitive screening, without any drug use. That is why a confirmation test is needed to identify and quantify the exact substance. Which medicines and foods can distort a result is explained in false-positive drug test.

What determines the detection window?

Three things weigh heaviest. First, the substance itself: heroin is only briefly visible via 6-MAM, while morphine stays longer in urine. Second, frequency and dose, which lengthen the window with regular use. And third, the cut-off value of the test. A lower cut-off means even small amounts test positive. What a cut-off involves exactly is explained in what is a cut-off value.

Drinking a lot of water does not reliably shorten the window. Dilution lowers the concentration temporarily, but a certified lab recognises a diluted sample by, among other things, the creatinine level. The Dutch Farmacotherapeutisch Kompas describes the pharmacology of opioids and their breakdown; it shows that only time genuinely shrinks the window.

Which test fits your question?

If you want opiates measured reliably, a certified lab test is more accurate and easier to defend than a test strip. Opiates and the heroin marker 6-MAM are included in our extended 10-panel. If you are unsure between urine, saliva or hair, which drug test suits you helps further. The broader overview per substance is in our pillar how long do drugs stay detectable.

Figures on opioid use and health incidents in the Netherlands are kept by the RIVM; the WHO describes the risks of long-term opioid use. Those sources say nothing about your personal window, but they do explain why employers and the CBR use testing.

Frequently asked questions

Can poppy seed give a positive opiate test?

Yes, it can. Poppy seed contains traces of morphine and codeine, enough to trigger a sensitive screening. A confirmation test and the presence of 6-MAM help to distinguish food sources from genuine heroin use.

What is the difference between opiates and opioids?

Opiates are the natural substances from the poppy, such as morphine and codeine. Opioids is the broader term that also covers synthetic agents. A standard opiate screening mainly targets morphine and codeine and misses some synthetic opioids.

Does a positive result prove current use?

Not necessarily. A urine result shows use within a window of days, not current impairment. Saliva and blood are closer to recent use.

Detectable is not the same as under the influence

A positive opiate test does not prove someone was under the influence at the time of the test. Morphine can still be detectable in urine days after use, while the direct effect is long gone. A urine result therefore shows exposure within a window, not current impairment. Saliva and blood are closer to very recent use, while hair shows a pattern over months.

That distinction matters when drawing conclusions. A high or low cut-off also shifts the line: with the same amount, one test can be positive and another negative, without either being wrong. That is why a disputed result always calls for a confirmation that shows the exact substance and concentration.

The windows in this overview are guide values and no guarantee; the outcome differs per person. Every test result at Zuivertest includes a professional assessment by a BIG-registered doctor. If you have concerns about your health or about substance use, discuss this with your general practitioner.