Can Diet Pills Cause A Positive Drug Test?
In our latest question and answer, the pharmacist discusses whether or not diet, or weight loss pills, are associated with failed drug tests for methamphetamine or amphetamine.
I would like to know what I could have taken to trigger a positive urine test for methamphetamine and amphetamine. I was taking diet pills, Wellbutrin, allergy pills, and nasal spray.
Nov 01, 2022- Diet pills can contain unlisted ingredients like amphetamines or ephedra that may cause a positive drug test result. Dietary supplements are not regulated by the FDA before being sold, so many products contain different ingredients than what's listed on the label. Some common ingredients in diet pills and other medications can cross-react with drug tests and produce false positive results for amphetamines.
Answer
There is certainly a chance that your diet pills were the cause of your failed drug test. Dietary supplements are not tested for their contents, purity, or potency prior to the sale and marketing of the products by a governmental agency. The FDA typically only takes action on dietary supplements if there is a clear abuse of marketing health claims or if they receive complaints about adverse events.
Adulterants In Supplements Or False Label Claims Are Widely Reported
The lack of FDA oversight and the dubious label claims of some over-the-counter supplements has been well noted.
Many studies have pointed out that a large number of dietary supplements do not contain the listed ingredients and may contain adulterants or unlisted ingredients.
One of the more recent well-known actions that resulted from these studies are the cease and desist letters the New York attorney general sent out to various supplement retailers for false labeling claims that targeted many private label brands owned by popular retailers (e.g., Target, Walmart, Walgreens, and GNC).
The FDA as well sends a large number of warning letters every year to supplement manufacturers for products that contain unlisted, or adulterated ingredients.
Amphetamines In Dietary Supplements
In regard to amphetamine or methamphetamine specifically, there have been reports of diet pills containing these substances, or similar stimulant products that could possibly result in a positive test.
For example, ephedra, which was banned in 2004, was known to cause positive tests for amphetamine. Although banned, supplements are still being reported for adding ephedra as an unlisted ingredient.
Even if a diet pill doesn't contain amphetamine or methamphetamine specifically, urine drug tests are notorious for false positives due to the cross-reactivity of similar drug molecules. For example, Wellbutrin (bupropion), desipramine, phenylephrine, and ranitidine have all been reported to cause false positives for methamphetamine on drug tests.
So while it's difficult to definitively say whether or not your diet pill resulted in a positive methamphetamine drug test, that is certainly a possibility. If you are going to be taking over-the-counter diet pills, be sure to at least stick with reputable manufacturers.
Final Words
I hope you found this answer helpful. Please reach back out anytime.
References & sources
- Commonly prescribed medications and potential false-positive urine drug screens — PubMed
- Ephedra — NIH
- Some Weight Loss Supplements Contain Amphetamine-Like Compound — LiveScience
- Cease and Desist Letters — New York Office of the Attorney General
- Warning Letters Related to Food, Beverages, and Dietary Supplements — FDA
Glossary — Terms in This Answer
- Adulterants
- Unwanted or harmful substances that are mixed into a product, either intentionally or by accident.
- FDA
- The Food and Drug Administration, the U.S. government agency responsible for regulating food, drugs, and dietary supplements.
- Dietary supplements
- Products taken by mouth that contain ingredients intended to supplement the diet, such as vitamins, minerals, or herbs.
- Amphetamines
- A class of powerful stimulant drugs that speed up the nervous system and can be detected on drug tests.
- Methamphetamine
- An illegal stimulant drug that is chemically similar to amphetamine and commonly tested for in drug screenings.
- Ephedra
- A plant-based stimulant ingredient that was banned by the FDA in 2004 due to safety concerns.
- Cross-reactivity
- When a drug test incorrectly identifies a different substance as the drug being tested for because the molecules are chemically similar.
- False positives
- Test results that incorrectly show the presence of a drug when the person did not actually take that drug.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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