Last updated : April 21, 2025
If someone is scheduled to take their first drug test, it can be nerve-wracking—even if they don’t use drugs. There are lots of myths floating around online that may or may not be true. Doing something that could cause a false positive result after finally landing the interview of a lifetime would be devastating.
However, trying to refrain from doing this or eating that “just in case” is no way to live your life. For the most part, it’s perfectly fine to eat before a drug test. That is, unless, you’re scheduled for an oral fluid test and have heard stuffing your face full of fatty foods on the way to the facility is going to hide the fact that you smoke pot.
Advice found online suggests that this technique traps the THC metabolites floating around in your mouth. Thereby, none will be detected on the test. Yeah, that won’t work because the body is constantly producing saliva. It doesn’t take much reasoning to debunk that method of madness.
Some foods have caused problems with drug test results though. If one is eaten before the test, it might cause a false positive result.
Let’s take a look at them.
Pizza
Yes! This food—considered a diet staple by many—could trigger a false positive on a drug test. It’s due to the yeast used to make the crust rise. Yeast ferments sugar into alcohol—and it can also show up as THC on a drug test! Rather than risk it, it’s best to lay off the pie for a few days before you take the test.
Hemp seeds
Did you know that people eat hemp seeds? They’re found in snack bars, granola, and other foods, so check the ingredient list if you’re a fan of these snack foods just to be safe. Hemp comes from the same plant family as marijuana and there are varying levels of THC found in it. Hemp seeds wouldn’t contain a lot of THC, but it accumulates in the body, so heads up.
Poppy seeds
Not so long ago, people did test positive for opiates after eating poppy seed bagels and other foods containing them. That’s because even though the seeds themselves don’t contain the narcotic, opium alkaloids, such as morphine and codeine, attach to the seeds during the harvesting process.
Once the problem came to light, it was easily corrected though. The test levels were raised to a higher level—problem solved. Of course, distributors were notified of the issue as well to ensure seeds were well washed before putting them on the market to be sold in the United States.
Sadly, in late 2019, the Drug Enforcement Administration (DEA) released information about a growing problem. Seed harvesters, looking to benefit from the narcotics industry, intentionally make small cuts in the opium pods as they begin to ripen. The milky white poppy latex, then, covers the seeds with a thick coating. They market the seeds as “unwashed” which, of course, is a code for drug users. Amazon and some other major marketers have quit selling unwashed seeds to help fight the problem.
According to the information, people purchase the seeds and use them to make tea which contains “sufficient amounts of alkaloids to produce psychoactive effects.” There were at least 12 reported deaths associated with poppy seed tea brought to light by 2019.
Coca tea
Coca leaves do contain cocaine and if you have enough accumulated in your system, it’s going to cause you to pop positive for the drug for up to 36 hours after consumed. It’s probably a good idea to try a new flavor for a few days… mint maybe?
Tonic water
You may have thought the only problem with drinking water before a drug test is that you could receive an inconclusive result due to a diluted specimen if you drink too much. Wrong! Tonic water contains quinine. It’s used to cut street drugs, like heroine, for instance, to increase the amount of drugs for sale. Even small traces of it can trigger a false positive result on your drug test.
Durian
This prickly Asian fruit is more than just smelly. It leaves enough “mouth alcohol” behind that it can cause a positive breathalyzer result. In 2019 several officers in the Jiangsu Province of China refused to believe it could be possible. They tried the fruit themselves and then tested positive with a blood alcohol level of 0.016%—above the legal limit.
Other substances can cause positive results
A few other culprits that can cause a false positive result on a drug test include some over-the-counter medications and, we were surprised to discover that a certain soap could even be a trigger!
The list includes:
Antibiotics
Certain antibiotics, namely fluoroquinolones and rifampin, have been known to cause false positive results on drug tests. The instances are extremely rare though.
Antihistamines
Common antihistamines contained in over-the-counter allergy and cold medications can cause “mirror images” of methamphetamine. Rather than temporarily being pegged as a meth head, be sure to alert your test technician of any medications that you’re taking.
Ibuprofen
This anti-inflammatory drug (NSAID) helps reduce pain, fever, and inflammation. There have been rare cases reported, published in the Journal of Clinical Chemistry: there is a “small likelihood of a false-positive immunoassay test result for cannabinoids, benzodiazepines, or barbiturates after the acute or chronic ingestion of ibuprofen.”
Baby soap
We found this hard to believe, however, soaps that leave babies smelling as only babies can smell could cause their parents to trigger a positive THC response on a drug test. We’re quoting the study published in the Journal of Clinical Biochemistry here, “commonly used soap and wash products used for newborn and infant care as potential causes of false positive THC screening results.”
The study noted the importance of documenting this information because a false positive THC result could lead to social services being involved or false allegations of child abuse against the parent.
Yikes.
One drug test tests the drug tests
If someone is falsely accused of testing positive for drugs, a blood test can clear up any question. Blood tests detect both the parent drug and its metabolites. In short, that means a person tests positive if there is any form of drug in the system when the blood for testing is drawn.
Instead of having to endure that, though, being aware of foods that can cause a false positive allows you to avoid them. Medications you regularly take should be disclosed at the time of the test as well—just in case.
Employers do everything possible to provide their employees with a safe work environment. Drug testing ensures the workplace is as safe as possible because it’s a means of weeding out the employees who use drugs. Of course, they realize that the majority of their employees don’t use drugs and won’t hesitate to work with employees who claim that a positive drug test result is unwarranted.
Still, if avoiding these foods and medications ensures there won’t be any false positives, it’s worth avoiding them until after the test.
