Do Muscle Relaxers Show Up on a Drug Test?

If you’re taking muscle relaxers—whether for muscle pain, muscle spasms, or chronic conditions like multiple sclerosis—you may be wondering: Do muscle relaxers show up on a drug test? The answer isn’t always simple, and it depends on several factors, including the specific muscle relaxer, the type of drug test, your metabolism, and whether the test is a standard or extended panel.

This article is written to help you or a loved one understand how muscle relaxers interact with drug screening tests, and why it matters—especially for those in recovery, safety-sensitive industries, or under medical supervision.

What Are Muscle Relaxers?

Muscle relaxers, also known as muscle relaxants, are medications commonly prescribed to reduce muscle tension, alleviate pain, and treat muscle spasms. These spasms can result from injuries, nerve damage, or conditions like multiple sclerosis or spinal cord injuries.

There are two primary types of muscle relaxers. Centrally acting muscle relaxants affect the central nervous system and are often used for muscle spasticity. Peripherally acting agents act directly on muscle function at the site of the spasm.

Some of the most common muscle relaxers include:

• Cyclobenzaprine (Flexeril)
• Carisoprodol (Soma)
• Methocarbamol (Robaxin)
• Tizanidine (Zanaflex)
• Baclofen (Lioresal)
• Diazepam (Valium)

Each of these medications has a different half-life, meaning the time it takes for half the drug to leave your system.

Do Muscle Relaxers Show Up on a Drug Test?

Most standard drug tests do not screen for muscle relaxers. However, certain muscle relaxers—especially those that are classified as controlled substances—can be detected if the test is specifically designed to look for them.

Types of Drug Tests

Drug tests vary in sensitivity and scope. The most common types include:

• Urine tests
• Saliva tests
• Blood tests
• Hair follicle tests

Each of these has a different detection window, meaning how long a drug can be detected after use.

Standard vs. Extended Drug Panels

• Standard drug panels usually test for substances like opioids, THC, cocaine, amphetamines, and benzodiazepines.
• Extended drug panels or specialized drug tests may include muscle relaxants, but only if specifically requested.

For example, Carisoprodol (Soma) is a controlled substance and may show up in a standard panel. Cyclobenzaprine is not typically detected unless included in an extended panel.

Mandala Healing Center accepts the following insurance providers

Check if my insurance covers rehab

How Long Do Muscle Relaxers Stay in Your System?

Several factors affect how long muscle relaxers stay in your system, such as:

• The specific medication
• Dosage and frequency
• Your individual metabolism
• Liver function and kidney function
• Body mass
• Duration of chronic use

Here is a general overview of how long specific drug tests may detect muscle relaxers.

Urine Tests

Urine drug tests are the most commonly used in workplaces and treatment centers. While they typically don’t detect most muscle relaxers, drugs like carisoprodol or diazepam may appear, especially in extended panels.

Blood Tests

Blood tests can detect recent drug use but have a shorter detection window. They’re less commonly used for routine drug screening but may be used in emergencies or accidents.

Saliva Tests

Saliva tests are quick and less invasive, but they only detect substances used within the last 24–48 hours. They’re not ideal for identifying muscle relaxers, unless administered soon after ingestion.

Hair Follicle Tests

Hair tests have the longest detection period, sometimes showing drug use from up to 90 days ago. However, they are expensive and typically reserved for specialized drug tests.

Can Muscle Relaxers Cause a False Positive?

Yes, some prescription medications—including certain muscle relaxers—have been known to cause false positives on drug tests.

For example. Cyclobenzaprine is chemically similar to a tricyclic antidepressant and may trigger a false positive for TCAs on some drug panels. Methocarbamol might occasionally be misread as an opioid or barbiturate in low-quality tests.

In these cases, confirmatory tests such as gas chromatography mass spectrometry (GC-MS) are used to clarify results.

Why Would Muscle Relaxers Be Tested For?

There are several reasons why a testing facility might include muscle relaxers in a drug screening. 

These situations include:

• You’re applying for a safety-sensitive job (e.g., operating heavy machinery)
• You’re in a substance abuse treatment program
• You’re under legal supervision (e.g., probation)
• You exhibit symptoms of drug use
• Your healthcare provider requests a broad-spectrum panel

If a specific muscle relaxer is suspected, it must often be specifically tested for. Most tests do not automatically detect these drugs unless specifically requested.

Medical Use vs. Misuse

When taken under medical supervision, prescribed muscle relaxers are generally safe for short-term use. 

However, high doses, prolonged use, or combining them with other central nervous system depressants (like alcohol or opioids) can lead to serious health risks, including:

• Drowsiness
• Respiratory depression
• Dependency or addiction
• Withdrawal symptoms

Some people misuse muscle relaxers to enhance the effects of other drugs. This non-medical use increases the chances they will be screened for during drug tests.

How to Handle Drug Screening if You’re Taking Muscle Relaxers

If you take muscle relaxers and are worried about taking a drug test, here are steps you can follow to ensure the best outcome.

Be Honest

If you’re prescribed muscle relaxers, disclose this before your test. Bring a copy of your prescription medications list, especially if your job or treatment center requires frequent testing.

Know the Half-Life

The medication’s half-life will affect how long it remains in your body. A shorter half-life usually means the drug leaves your system quicker, but chronic use may extend that timeline.

Request a Confirmatory Test if Needed

If your test results come back positive and you believe it’s due to a false positive, request a confirmatory test like GC-MS for accurate analysis.

Find Treatment and Support for Muscle Relaxer Addiction

So, do muscle relaxers show up on a drug test? The truth is: not always, but they can, depending on the drug, the type of test, and whether the testing facility is looking for it.

For those in recovery, using safe medication alternatives and communicating with medical professionals is essential. If you’re worried about testing, talk with your healthcare provider or addiction specialist to ensure you’re on a path toward lasting recovery.

If you or someone you love needs treatment or support to manage substance abuse, you are not alone. Find the resources, treatment programs, and recovery support you need at the Mandala Healing Center. Explore your treatment options or schedule an intake appointment by contacting us today. 

Frequently Asked Questions (FAQ)

1. Can you take muscle relaxers while in addiction recovery?

Yes, but only under close medical supervision. Some muscle relaxers have a potential for misuse, especially those that depress the central nervous system.

If you’re in recovery, it’s crucial to consult your treatment team before using any new medication—even if it’s prescribed. Safer, non-addictive alternatives may be available.

2. Are over-the-counter (OTC) muscle relaxers detectable on a drug test?

Most OTC options marketed for muscle pain relief, such as NSAIDs or supplements, are not true muscle relaxants and are generally not detected on drug tests. However, if an OTC product contains ingredients that mimic controlled substances or interact with other drugs, they could potentially cause a false positive.

3. Can a positive drug test for muscle relaxers impact your job application?

Yes, especially in safety-sensitive industries like transportation, construction, or healthcare. Even if you have a prescription, some employers may deem the use of muscle relaxers as incompatible with job duties due to sedation or cognitive effects. Always discuss medications with your HR department or occupational health provider.

4. Is it safe to combine muscle relaxers with mental health medications?

Caution is advised. Muscle relaxers can interact with medications used for anxiety, depression, or sleep disorders—particularly other central nervous system depressants. These combinations can intensify sedation or lead to complications. Your prescribing provider should review all your medications to prevent adverse interactions.

5. What should I do if I’ve been using a muscle relaxer without a prescription?

Using prescription muscle relaxants without medical guidance is considered misuse and may pose health and legal risks. If you’re doing this to self-treat pain, anxiety, or sleep issues, it’s important to seek support from a medical professional or addiction specialist. Treatment options are available, and help is accessible without judgment.

Sources

1. Medline Plus: Cyclobenzaprine
2. FDA: Cyclobenzaprine (Flexeril)
3. NIH: Muscle Relaxants
4. NIDA: Commonly-Abused Drugs Chart