Coca Tea

Drinking Coca Tea could lead to a false-positive result on a drug test for cocaine. The tea is made from the leaves of the coca plant, the same source cocaine is derived.  The tea is popular in South America but I can’t say that I’ve ever heard of it being a thing here in the states, but just in case it’s best you stick with Oolong.


Cold Medication

There are some over-the-counter cold medications that have the kind of ingredients in them that could show a false-positive for amphetamines like the ingredient in an antihistamine used in some cold medications called brompheniramine.  That ingredient can interfere with the test for methamphetamine, which actually makes sense since don’t they make meth with cold medicine or something? Fun fact, in the past the use of a Vick’s Inhaler nasal decongestant led to false positives for amphetamines because they contain levomethamphetamine, a chemical that could be meth’s twin. Although apparently in the study that got their information from newer drug tests can tell the difference between meth and the chemical in Vick’s inhalers so it’s all good.


Secondhand smoke form marijuana

This has been one of those “Is it a myth, or isn’t it” type of things that people talk about all the time when they’re either currently working somewhere that does regular drug testing or is getting ready to take a drug test for a new job.  In a study done in 2015, basically a group of non-smokers were sat next to some tokers who were then placed in a sealed chamber where the stoners then proceeded to hot-box the shit out for about an hour at which time the non-smokers were tested drug tested and yes, they did in fact test positive for marijuana in sensitive tests that aren’t at all like the ones they use in everyday drug testing.  Not to mention the fact that these are extreme circumstances and it’s very unlikely that someone for your job or potential place of employment is going to knock on the door of your friend’s apartment on a Saturday night at 2 a.m. to administer a drug test.



According to the article in there are certain antibiotics, like rifampin and fluoroquinolones, that can lead to false-positive results for opiates.  In a case reported in 2002, a 7-year old boy in Lebanon who visited the ER tested positive for opiates but it was then later determined that the rifampin he was taking had interfered with the drug test.  Why were they drug testing a 7-year old anyway?


Baby Soap

Often times newborn babies will get tested for drugs to determine if a mother was using drugs while pregnant, however, there are certain soaps that hospitals use to wash babies right after they are born that may cause them to test positive for marijuana. Those soaps include Johnson & Johnson’s Head-to-Toe Baby Wash, J&J Bedtime Bath, CVS Night-Time Baby Bath, Aveeno Soothing Relief Creamy Wash and Aveeno Wash Shampoo. Researchers say they aren’t sure why the soaps were causing the false positive results but that some of the compounds in the soap have a structure similar to THC.



In some very rare cases taking Ibuprofen in high doses could lead to testing positive for cannabinoid (a compound in marijuana) or even barbiturates.


Tonic Water

Did you know that tonic water contains small amounts of quinine, a drug used to treat malaria? It’s also used sometimes to mix with street drugs so it can sometimes be an indicator of illegal drug use.


HIV Medication

Efavirenz (brand name Sustiva), an antiviral medication used to treat HIV, can also cause people to test positive for the ole Mary Jane. Then again, if you’ve taking HIV medication you’re probably not worried about testing positive for the devils lettuce.


Poppy Seeds

Another of those things that people aren’t really sure if it’s true or not that does happen to be true. Poppy seeds have the compounds morphine and codeine in them naturally, so eating stuff with poppy seeds before a drug test could get you a little trouble, however, as with many of the other things on this list that could cause a false positive result on a drug test, it’s only in cases where the individuals haven ingested the food with poppy seeds in it and then are tested an hour later.  So enjoy your muffin.

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