What Medications Test Positive for Methamphetamines

Ever taken a routine drug test and been shocked by the results? You’re not alone. False positives especially for methamphetamine are more common than you might think.

What Medications Test Positive for Methamphetamines

What Medications Test Positive for Methamphetamines
Monday, June 16, 2025

Ever taken a routine drug test and been shocked by the results? You’re not alone. False positives especially for methamphetamine are more common than you might think. A positive test doesn’t always mean illegal drug use. Sometimes, it’s your medicine working against you. That’s why it’s important to know what medications test positive for methamphetamines and how to protect yourself from misunderstandings.

Why Drug Tests Matter

Drug tests are used in many areas: jobs, sports, schools, and even legal proceedings. So, when a false positive shows up, it can cause serious trouble—even if you’ve done nothing wrong.

 

The Confusion Around False Positives

Many prescription and over-the-counter (OTC) drugs have chemical structures similar to illegal substances. Because of this, they can “trick” standard drug tests. Understanding which medications are responsible helps you stay safe and proactive.

 

Understanding Methamphetamine Testing

How Methamphetamines Are Detected

Meth is usually tested in urine, but can also be found in blood, saliva, or hair. Most preliminary tests look for metabolites that are present after methamphetamine use but they aren’t always accurate.

 

Types of Drug Tests Commonly Used

Urine Test

The most popular method. Quick, cheap, but more likely to show false positives.

Blood Test

More accurate, but also more invasive. Rarely used for routine screenings.

Hair Follicle Test

Can detect drug use for up to 90 days, but it’s expensive and not as commonly used.

 

What Causes a False Positive for Methamphetamine

Cross-Reactivity in Drug Tests

Some substances can confuse the test because they interact similarly to meth in your body. This is known as cross-reactivity.

Impact of Similar Chemical Structures

Methamphetamine belongs to a group of stimulants. Medications with similar backbones can be misidentified by basic testing methods.

 

Common Medications That May Trigger False Positives

Prescription Medications

Bupropion (Wellbutrin)

Used for depression and smoking cessation. Its structure mimics meth, leading to false flags.

Selegiline (Eldepryl, Zelapar)

A Parkinson’s medication that metabolizes into meth-like compounds.

Phentermine (Adipex-P, Lomaira)

A popular weight-loss drug. Chemically similar to amphetamines.

Ephedrine and Pseudoephedrine (Sudafed)

Found in cold medicines. Structurally close to meth, and often raise red flags.

Amantadine

Used for Parkinson’s and flu treatment. Another culprit of false positives.

Ranitidine (Zantac)

Previously used for heartburn. Known to occasionally cause methamphetamine false positives.

 

Over-the-Counter (OTC) Drugs That Can Cause False Positives

Cough and Cold Medications

Many contain pseudoephedrine or dextromethorphan—common ingredients known to interfere with drug tests.

Nasal Decongestants

Sprays like Afrin or tablets like Sudafed can mimic meth on urine screens.

Weight Loss Pills

OTC stimulants often share characteristics with methamphetamine, enough to confuse drug panels.

 

Illicit Substances vs. Prescription Stimulants

Structural Similarities

Both meth and some legal drugs belong to the amphetamine class, which is why cheap tests sometimes can’t tell them apart.

Why the Distinction Matters

Failing a drug test over a medication is unfair—and can cost you your job or reputation.

 

Legal and Employment Consequences of a False Positive

Losing a Job Over a False Result

Sadly, many employers act before getting full confirmation. That’s why you need to know your rights.

Legal Recourse and Testing Rights

You can request a retest. You also have the right to provide evidence of prescription use. Always keep your medical records handy.

 

How to Protect Yourself

Informing Your Employer or Tester

Always tell them beforehand if you’re on medication that could affect results.

Providing a Medication List

Bring a list of current prescriptions and OTCs you take. It may prevent unnecessary stress later.

Asking for GC-MS Confirmatory Testing

This secondary, more accurate test can clear your name. Always ask for it if you test positive and know you haven’t used illegal substances.

 

Confirmatory Tests: Your Best Defense

What is a GC-MS Test?

Gas Chromatography-Mass Spectrometry. It’s a highly precise test that separates and identifies each compound in your system.

Why It’s More Accurate

Unlike basic tests, GC-MS doesn’t just guess based on shape—it reads the compound completely.

 

Role of Doctors and Pharmacists in Educating Patients

Importance of Disclosure

Always tell your healthcare provider if you’re undergoing drug testing. They might help prevent or explain a false positive.

Advice on Handling Drug Testing Situations

Pharmacists can often provide printouts confirming that your prescription may trigger a false result.

 

Real-Life Cases of False Positives

Case Studies

  • A woman lost her job due to a false meth result caused by Wellbutrin.
  • A student was banned from sports because of Sudafed.

Lessons Learned

Always get a second opinion. Never accept a preliminary test as final without confirmatory results.

 

Summary Table of Medications and Their Risks

Medication Name Common Use Risk of False Positive
Bupropion (Wellbutrin) Antidepressant High
Selegiline Parkinson’s High
Phentermine Weight Loss High
Ephedrine/Pseudoephedrine Cold Relief Medium to High
Amantadine Flu/Parkinson’s Medium
Ranitidine Heartburn Low to Medium

Conclusion

False positives on drug tests for methamphetamine can be stressful and damaging—but they’re not uncommon. Knowing what medications can cause this, being proactive with information, and always requesting confirmatory testing can save your job, reputation, and peace of mind.