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Will cyclobenzaprine show up on drug test?

4 Answers

Koljohnson07 29 June 2018

I know this is an old question, but it is one I see many times. I work in toxicology testing, performing data analysis for drug tests both in the work place and for pain management. I just wanted to reply so that other people may find the answer.

Short answer: yes it can show up, no it is not on a typical UA panel for confirmation but it cross reacts with a screen on the pee cup, it is not a TCA, but it does give a false positive for the TCA screen on the POC cups. TCAs are commonly checked on those cups now, if this happens to you, it will be sent for confirmation for the TCA panel and come back negative since Cyclobenzaprine (Flexeril) is not actually a TCA.


Long answer for those curious:
Cyclobenzaprine (Flexeril) can show up on drug tests. While previously TCAs were not routinely screened for for work place drug testing, I have seen many point of care testing cups have this screen on them (just took one today for a job with it on it). Cyclobenzaprine is not a TCA. That is true, however, with point of care testing cups and all screening sources for that matter, it will yield a false positive. Your sample will then need to be sent out for confirmation. In order to proclaim you as nok compliant or violating the terms of your employment, you need both a positive screen and positive confirmation. Since Cyclobenzaprine is not actually a TCA, once your sample is tested for confirmation, it will come back negative for the TCA panel. Some panels can tests for cyclobenzaprine in confirmation, however this is not routinely done and would be a separate test requested outside of the TCA confirmation panel. I have only rarely seen this done and never in the work place situation. Usually only for doctors wanting to check that their patient is taking it to confirm if it's not working or they're not taking it or if they see the point of care cup as positive for the screen and keep getting negatives on the confirmation they may request it to be certain the interference is due to this drug.

I know this to be true because today my POC cup flagged barely positive for TCAs. I have never been on TCAs but do have a script for cyclobenzaprine and took one 2 to 3 days ago. The first time I did not produce enough to send out so I had to wait, drink water, and take another one. The second time because it had been about 3 days since I last took one and the sample was so dilute it came back negative and it was all kind of a waste of my time for something I knew was a false positive to begin with but hey they have to check. I got a copy of the panels they test for on my discharge sheet and was able to confirm this was the only non illegal drug being tested for in the POC cup. I was also asked after the first sample if I took medication because they were waivering on whether or not to call it positive or negative since it was so faint. I told them I did and thus had to redo it. Anyways, just wanted to throw in my experience as well as my knowledge because some people say "yeah, it's a TCA" other's correct them and say "no it's not" and then others will say "they don't even test for it". The truth as you can see lies somewhere in the middle and thus why there's so much confusion. Hope this helps anyone in search of answers! It's always good to know what's happening to your bodily fluids and how they are being handled regardless of whether or not "you're guilty". It's your sample and you're right to be educated on the process.

Votes: +0
Tlw0426 14 Feb 2017

If it is a standard pre-employment drug screen it WILL NOT show up. I know from recent experience.

Votes: +0
Llopez11967 10 Jan 2018

Was that all you were taking?

Inactive 14 Dec 2010

Hello gene,

The basic drug test used by testing programs for work, school, sports and legal checks for five groups of substances such as cannabis, cocaine, amphetamines, opiates and phencyclidine. Cyclobenzaprine being a muscle relaxant and not coming under any of the five groups listed above. Hence, urine drug test does not include Cyclobenzaprine.

However, there are urine tests available that are capable of detecting the presence of more than 200 chemicals. The presence of any drug including Cyclobenzaprine can be detected through these tests.

Just in case take your prescription with you and let them know you are on this medication before they do the test.

All the best,

Votes: +2
Inactive 14 Dec 2010

"Cyclobenzaprine is a muscle relaxant medication used to relieve skeletal muscle spasms and associated pain in acute musculoskeletal conditions. It is the most well-studied drug for this application, and it also has been used off-label for fibromyalgia treatment."


oxyaaron 14 Dec 2010

no, it is only a muscle relaxer and should not show up.

Votes: +0 free discount card

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