Vicks Inhalers Can Trigger False Positives on Drug Tests

If you've ever used a Vicks VapoInhaler to clear your stuffy nose, you probably weren't thinking about drug tests. But here's a wild fact: using this over-the-counter decongestant could make you test positive for methamphetamine on an initial drug screening. Yes, really.

The Chemical Twist

The culprit is levmetamfetamine (l-methamphetamine), the active ingredient in older Vicks VapoInhaler formulations. It's a close chemical cousin to illegal methamphetamine (d-methamphetamine), but with one crucial difference: they're mirror images of each other at the molecular level, called stereoisomers.

Think of them like your left and right hands—same structure, opposite orientation. L-methamphetamine works as a nasal decongestant with minimal effects on the brain, making it completely legal. D-methamphetamine? That's the illegal stimulant.

Why Drug Tests Get Confused

Initial drug screening tests, typically immunoassays like EMIT® II Plus, aren't sophisticated enough to tell these mirror-image molecules apart. Studies show these tests produced 2.2% false-positive results when people used Vicks inhalers as directed. If you exceeded the recommended dose, your chances of triggering a false positive increased even more.

One documented case involved a patient who tested positive for methamphetamine repeatedly. The mystery was solved when doctors discovered he'd been using Vicks VapoInhaler daily for respiratory issues. Soon after he stopped using it, his tests came back clean.

The Good News: Confirmatory Testing Works

Here's where science saves the day. When samples undergo confirmatory testing using gas chromatography-mass spectrometry (GC-MS) with enantiomer-specific methods, the legal l-methamphetamine is easily distinguished from the illegal d-methamphetamine.

Research conducted with controlled Vicks VapoInhaler administration found that no d-methamphetamine or d-amphetamine was detected in any urine specimens using proper GC-MS testing. The confirmatory test can tell your stuffy nose medication apart from actual drug use.

The 2014 Formula Change

Plot twist: In 2014, Vicks reformulated their VapoInhaler to a homeopathic version, removing the levmetamfetamine entirely. So newer inhalers shouldn't cause this issue at all. However, older inhalers containing l-methamphetamine might still be sitting in medicine cabinets or available in some markets.

This quirky intersection of chemistry and drug testing has caused real headaches for unsuspecting people—from military personnel to employees facing workplace screening. The takeaway? If you use or have recently used a Vicks inhaler and face a positive drug test, request confirmatory testing. It's your scientific alibi.