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Clonazepam - What would make Klonopin not show up on a drug screen?

27 Answers

Wiley111 5 hours ago

I can think of three reasons why Clonazepam (or any drug) might not show up on a drug screen:

1. The dosage was too low.
2. Too much time passed since the drug was taken, so it was mostly out of the person's system.
3. The drug was not included in the list of drugs being screened.
4. The lab is incompetent.

Votes: +1
Bishopmagicjuan 15 hours ago

I'm also on Klonopin, I notice if I drink a lot of water it will not show up in my system, yet the Dr says it should be in my system up to a month. I video tape myself taking it. But they only care about the urine test. Someone above said to file a grievance, can I ask how this works ? Who do I file it with, because I take my pills, I do not understand why they are not showing up. I can use some help please.

Votes: +0
ShaneAM311 13 Dec 2021

I have taken clonazepam for 10+ years and it never shows up on urine tests for me either. I always thought it was due to other medications I take that could possibly mask it. If you request they test your pee and send it into the lab they can detect minor traces in it I have found as well. Weird though.

Votes: +0
Luckyterry 28 June 2022

I’m prescribed Xanax but ran out so I took 2 Meg’s of klonopin and then was called in for a urinalysis. Later that week my Dr warned me to stop taking klonopin due to the fact that I’m not prescribed it. They can tell the difference.

skfreedman10 2 Dec 2021

Research has shown that this is true. It has to do with how klonopin is metabolized. Even in a lab, it might not show up it they use GC/MS testing. For some reason there are people who continue to maintain that there is not reason for it. They are misinformed, or under informed. "It does not react well by the commercially available screening reagents" If you want more detailed information, please look up research by Dr. Peter Abaci, as well as many others!

Votes: +2
mmmousemaid 18 Nov 2021

You have to look for it to find it.

Votes: +0
Numd2it 18 Nov 2021

Just adding to the chorus here, I take clonazepam daily and diazepam occasionally for emergencies and I have had problems with them not coming up on my drug screens at my methadone clinic. Apparently because of the way the metabolites work clonazepam is especially prone to false negatives. (the clinics will not do blood tests or anything else). Some doctors are aware of this and you can find info about it online but that didn't stop me from being accused of selling my medication. I actually had to switch methadone clinics because of this problem. I live in fear of having my meds taken away because of this and it's frustrating that more doctors aren't informed and that people are generally treated with suspicion when they don't deserve it. When it comes right down to it drug tests are an imperfect tool and should never be treated as infallible.


Decisions that have life threatening/ changing consequences, like taking away someone's anxiety meds or violating someone for probation should never be made based solely on a drug test. They should be a tool among many other tools like conversation and observation, pill counts etc. If drug tests weren't given godlike credibility and power over people's lives then things like this odd problem with clonazepam wouldn't have such terrible consequences for people who aren't doing anything wrong. It's a problem of education about how tests work as well as a problem of perspective on how drug tests should be used.

Votes: +1
BJK73 27 Jan 2021

It would stay in my system for 3 days. Every time I'd pass. I guess it depends on your metabolism...

Votes: +0
IMRight 27 Sep 2020

I am 39 years old, I take 4 mg of klonopin daily, for over 15 years. In that time I have been placed on drug court, twice, due to other things. Drug court is extremely strict probation, we have to call every morning, 365 days of the year, to see if we take a UA that day. We get called a minimum of 4 days of every week, Klonopin HAS NEVER shown up in my UA's... I take my medication as prescribed, it has NEVER, throughout all these years shown up. I am given a 15 panel UA, which obviously tests for benzo's, the tests are very sensitive as I smoked CBD that contained no THC, and it caused a false positive for THC. So for you people saying that's not possible, IT IS POSSIBLE AND DOES NOT SHOW UP FOR MOST PEOPLE. I HAVE TAKEN WELL OVER 200 UA's and my klonopin DOES NOT, I REPEAT DOES NOT EVER SHOW UP, NO MATTER WHAT TIMES I TAKE IT.


I don't have the explanation as to why, I'm just answering to inform all these people who answered that it isn't possible, that it is possible. I live it, I know for a fact.

Votes: +2
Mark Albus 4 June 2020

Will vinegar cover up Klonopin in a ua? What will really cover it?

Votes: +0
Dopefein1108 6 Feb 2020

There's a hundred different answers here. Klonopin has a longer half-life than Xanax. But does not always show up on UAs. Don't know why, and you don't know when it will or won't. But it sometimes doesn't. Maybe depends on water intake, other drugs, kidney functions or liver functions for that period, metabolism, who knows. But in my case, it would show up sometimes, sometimes not. Same dose, same times, just did what it wanted. To be sure it's out, if you take it once or twice, give yourself 5-6 days, and hydrate yourself just in case.

Votes: +1
DaynaE 5 Feb 2020

I take .5mg clonazepam 3x a day and it NEVER shows up on a in office drug screen. I've been drug tested once at the doctors office and my meds were withheld because it didn't show up on the screen. I eventually got my meds back 3 weeks later but although the .5's are still able to control any anxiety that I might have, it just never shows up on the tests... I'm fairly certain it's because of the way my body metabolizes medicine but my doctor didn't seem impressed with that answer when I told her that lol.

Votes: +0
Weaverwanda3 24 July 2019

Only not taking klonopin can result a negative drug screen.

Votes: +0
cleaner123 25 March 2019

I have been on klonopin for 30 years and it just recently the past 6 months stopped showing up in my weekly screenings and my rehab wants to know why. I think they believe I'm selling them. I am so scared they are going to take me off. I heard from some workers at the rehab that it is because I am on 2 different water pills.

Votes: +0
TKMarsh711 25 July 2019

Probably because the generic Klonopins now aren’t very good.

Birdflu 30 June 2018

I’ve been on clonazepam most of my adult life. I’m also on parole so I take drug screens regularly. clonazepam has NEVER shown on any of my drug tests. I would estimate I’ve had 15 screens over 3years and its never shown once. 2mg twice a day.

Votes: +1
14dw88 17 May 2018

I've had this problem so many times this last time the doctor took me off 2mg 3 times a day to 1mg 3 times a day women doctors are the worst so i took one in front of her to prove a point. They sent it to the lab the first one was one that had the results on the jar i tried to tell her that this has happened at least five other times for some reason they don't always show up but she doesn't like prescribing them anyways she said so i said i just want to make an appointment with a real doctor not some glorified nurse.

Votes: +2 free discount card

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