Every few months, I stumble across an account from someone who claims to have failed a drug test due to a poppy seed bagel, muffin, or bread. On one hand, that sounds like an awful experience. On the other hand, could a tablespoon of teeny seeds really be the culprit? A cursory online search yielded a Cerberus of uninformed speculation, contradictory answers, and flat-out conspiracies. So, I posed the question to some actual toxicology experts: Could poppy seeds make you fail a drug test?
To start, it’s important to know how these seeds affect the body. Most drug tests, called an immunoassay test, screen a person’s urine for morphine and metabolites (breakdown products) of morphine, which can indicate the presence of both heroin and cocaine. Because poppy seeds come from the poppy plant, as does heroin, the seeds contain trace amounts of morphine and related chemicals. Depending on the way specific poppy seeds are processed, just how much of those trace amounts they contain varies widely.
Andrew Stolbach, a medical toxicology and emergency medicine physician at The Johns Hopkins Hospital in Baltimore, tells The Takeout there could be as much as 30-fold variability in terms of how much morphine the seeds contain, depending on how they’re processed.
“A small package of poppy seeds is about 35 grams. To put it in perspective, to get what would be considered a standard dose of morphine with what we typically see as the amount of morphine in poppy seeds, you’d have to take all of the small container. And on the lowest reported end [of morphine concentration], you’d have to take all of a big container, nearly a pound,” Stolbach says.
Still, that does mean it’s possible that poppy seed bagel lovers could fail a drug test, especially if they’ve consumed said bagel within 12 hours of the test. The National Institute On Drug Abuse notes that poppy seeds could raise the levels of opium-derived chemicals in a person’s body for up to three days.
“Different suppliers might process their poppy seeds differently, but all are risky for the testing,” says Charles Chavkin, a professor of pharmacology at the University of Washington School of Medicine in Seattle. “It depends on the threshold used by the test, but a couple of poppy seed muffins or bagels could be sufficient.”
Poppy seeds can also, in rare cases, be toxic. Chavkin says that could occur if a person makes a very strong tea from the unripe capsule of the opium poppy, but it’s not likely at all with standard muffins or bagels.
In order to prevent positive test results due to poppy seed consumption, the federal government in 2017 raised its threshold for morphine to 2,000 nanograms per milliliter from 300 nanograms per milliliter.
“By raising the cutoff, they’ve reduced this poppy seed problem by a great deal,” Stolbach says. “Now, it’s possible [to fail the drug test] if you really eat a lot of poppy seeds, but it’s unlikely.”
If a person does fail an initial drug test, they might be asked to do a second confirmatory test, Stolbach says. At that point, the person should point out that the positive result was due to their ingestion of poppy seeds—and make sure to skip the poppy seed muffin beforehand.