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.

Question

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.

Asked by Tdk On Nov 01, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Nov 01, 2022
Last updated Mar 29, 2024

Key points

  • Dietary supplements do not have the level of government oversight that prescription drugs do and are not tested in an official capacity to determine whether their contents match label claims prior to their sale.
  • Certain dietary supplements have been reported to contain adulterants or unlisted ingredients, resulting in warning letters from the FDA.
  • It is possible that dietary supplements intended for weight loss could contain unlisted ingredients or ingredients that are similar enough to amphetamines, which could lead to a positive drug test.

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

  • 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

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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