How Long Does Klonopin Stay in The System, Blood and Urine?

Last Updated: December 18, 2019

Authored by Olivier George, Ph.D.

Klonopin has a long half-life, which varies between 18.7 and 60 hours. That means that it might take between 4.29 and 13.75 days for the drug to leave the system of the user. In other words, one might need up to two weeks to get clean from Klonopin.

Can One Be Tested Positive for Klonopin?

Klonopin is a powerful benzo, and as such, it can be detected by various drug tests. Blood, swab and urine tests can detect the drug for up to 5-6 days, while hair tests have a longer window of detection, up to four months. Note that acidic environments can help to excrete the drug quicker.

How Long Does Klonopin Stay in The System?

Blue Pills
Klonopin or Clonazepam is a habit-forming and life-threatening benzo. Therefore, users should be aware of the duration and the elimination of the drug. Its half-life ranges between 18.7 and 60 hours.
These figures suggest that it might take between 5 and 14 days for the drug to leave the system of the user.
In other words, one might need up to two weeks to get clean from Klonopin.

Factors That Affect Klonopin Duration & Excretion

As we can see, nobody can predict how long Klonopin will stay in one’s body. Some users need only a few days to get clean, while others – a couple of weeks. That’s because each case is unique.

In general, we can say that the following factors determine how long Klonopin will stay in the system:

  • Dosage
  • History of intake
  • Polydrug abuse
  • Age
  • Body mass
  • Genetics
  • Overall health
  • Food intake
  • Urinary pH

However, many individual factors can affect the duration and the elimination of the drug.
Note that patients with hepatic problems may need more time to clean their system from Klonopin.

Klonopin Metabolism Process

One of the important factors that affect Klonopin duration and elimination is the metabolic rate of the user.
The drug undergoes hepatic metabolism. Note that less than 2% of Klonopin is excreted unchanged in urine.
Last but not least, we should say that Klonopin binds to plasma proteins and fat stores, which leads to extensive distribution in the system.

Klonopin & Drug Testing

Although Klonopin is a potent benzo, testing for it is not common. However, various tests can detect the drug.
Remember that one needs 5-7 days of consistent administration to reach some steady levels within the body, even small doses can lead to positive results.

How Long Does Klonopin Stay In The Blood?

Blood peak concentrations can occur as soon as one hour after intake. Therefore, the best time for a blood test is 1-2 hours after ingestion.
However, blood tests can detect the drug as soon as few minutes after intake for up to few days.
Note that as these tests have a short window of detection and are quite invasive, they are reserved mainly for hospitalized patients.

How Long Does Klonopin Stay in The Hair?

Hair tests provide a long window of detection, up to four months. Thus, hair tests can reveal a lot about the history of abuse.
We shouldn’t forget that the best time for a hair test is few days after ingestion as it takes some time for the metabolites to appear in hair segments.

How Long Does Klonopin Stay in The Saliva?

Saliva tests are a great option in the case of intoxication.
That being said, detecting Klonopin and its metabolites in oral fluids is more difficult compared to other tests.
Swab test can detect the drug for 5-6 days after intake, with a cut-off level of 1 ng/ml.

How Long Does Klonopin Stay in The Urine?

Urinalysis is the most preferred method for the detection of Klonopin and its metabolites.
Urine tests have cut-off levels of 30 ng/ml and can detect the drug for up to 5 days after intake.
Some studies claim that users may test positive for up to 30 days after their last dose.
Note that some acidic foods can help to excrete the drug quicker.
Still, the best way to test negative and stay safe is to say no to Klonopin abuse.

Page Sources


Published on: June 14th, 2017

Updated on: December 18th, 2019

About Author

Olivier George, Ph.D.

Olivier George is a medical writer and head manager of the rehab center in California. He spends a lot of time in collecting and analyzing the traditional approaches for substance abuse treatment and assessing their efficiency.


Leave a comment

  • Jonny
    If I only took .25 of Klonopin and got a drug screen 2 and a half days later am I ok?
    • Slim
      Did you pass your test please let us know
  • Donna L Smith
    I have been on 1to2mg. For 6 years. How long will it take me to detox? I have also taken 1/2 in the morning and half at night for most of those 6 years
  • Donna
    Also how long after taking 2 klonipins will you have a dirty urine?
    • Connie
      Brand new to using site. How long it take the 2 pills to clear your system
    • Artie Dillard
      How long will one dose of clonipin 1mg stay in your system if you are required to do. Urine the next morning.
      • Jodi
        Around 5 days ..
  • Brandon Lee Morales
    I took .05 of clonazpeam and have a swab on monday today is tuesday wil i pass?
  • Matthew
    If I take a 1mg colonopin on Monday night will it be deleted with heavy water drinking till Thursday at 3pm
    • chris
      Sounds as if you drink or eat acidic food you have a better chance of passing it somewhat quicker. I have no exact details on this but depends on consistent use and other factors.
      • Dan
        Cause acidic foods like lemon, grapefruit, oranges all juiced with some juice ginger is a detox drink it’ll flush them kidneys out
      • Dan
        Yes acidic food (juices will flush you out. Squeeze grapefruits,lemon,oranges and juice ginger,,it’ll detox you and clean ur kidneys out.. Do this for a few days on a empty stomach in the morn and itll flush you reall good
  • Liz
    Years ago I was prescribed 1mg 3x daily for 2 yrs. I entered treatment for a drinking problem and was not allowed to take my medication plus they tested weekly. I tested positive for 14 days with no benzo and no sleep for longer. They thought I was sneaking in benzos and I wasn’t. On the third week I tested clean. I am a woman, was then a 29yr old with average weight. No health issues or bad liver. I took a valium a few weeks ago and had to take a test for work, it was out of my urine in 5 days because it didn’t show up and this test was a lab test that tested for everything individually and not a quick cup.
  • Cheryl
    My question I have a urine test for klonopin I’m on1 mg twice a day but been sick n puking meds back up thanx two hernias I need to have my level urine test come back positive worried wat can I do I have severe PTSD n dont wanna lose my meds
  • Leighsalyn
    I have been on klonopin for over 20 years due to severe panic attacks and debilitating anxiety. It started with Xanax til they said klonopin lasted longer needed less doses taken in a day , so of course I’m in less is best to me. I had back surgery in 2012 had to go to treatment to get off opiates , never abused benzoes but still couldn’t have them there. They said klonopin was hard to detect in urine. Not sure about that but nothing more got said after 2nd day
  • Vince
    I took 2mgs of kolonopin one time 2 days ago my po wants me to test tomorrow will I be ok I only ate the one pill and been drinking water with niacin lmk asap please
  • Jorrie
    Hi Connie, I just found this site. I’m not quite sure if you got an answer. A dose of Clonazepam, being 1mg. can stay in a urine test or 2~3 days. If a person is taking it daily for a long period this is called chronic use & stays in system for 3 x the above #. I have not been able to get an RX for these & need them. Thanks to the Pill Governors no one gets what they need or others overabuse recklessly screwing the rest that could have but now can not get these. These weren’t always a C.S. now too many are!! :(, Dr’s can’t prescribe for fear of being written up or losing their hard earned Degrees in Medicine. Of course these others ie: Reagan Administration & Ron himself was a Pharmacist so he knew what was up!! Not. Politicians need to stay in their place. WE & ME THE PEOPLE THINK THIS IS A TRUE!! I’ve seen a # of answers so this didn’t help but from experience, if you’ve got an appt. in 7 days stop within 5-6. They can linger based on rate if metabolism. Clons stay in urine longer than the others. They work but DR’S don’t want to give to many patients a RX or a person HAS 2 to go to Mental Health & pay out more $ for another Healthcare provider. Our nation has the best insurance, co~pays & healthcare in the world!! Not again. People need to squeak or the wheels don’t get greased & we will all be allowed aspirin which will become a controlled substance. If we don’t pipe UP!! We will be broken.down & be in pain, loaded w/ anxiety & this is NOT A GOOD THING
    • Michele estrella
      How about on a swabs
  • Sue
    I took a total of four .5mg Klonopin on Saturday, will it be out of my system today? It was a total of 2mg one time.
  • Me
    I wanna know if I took 0.5 mg on Tuesday and have never taken it before or since will it show up on a UA the following Saturday?
  • Paula
    If you are taking 0.5 mg. of Klonopin per day, along with 20 mg. of Lexapro, how long do you think it would take to get off of the Klonopin?
  • Justin
    If I take2 klonopin will they be out of my system for a urine test in 9 days
    • Cedie
      If I took a Klonopin on a Tuesday when will I show up clean
  • Sharon
    If no clonazepam was taken for 3 weeks then 7- 1mg tablets was taken at once and he had a high tolerance, but usually it’s taken 1mg 3 times daily. Does a blood test show the 7 -1mg was taken at once? Can a blood test tell the difference when it’s usually taken 3 times daily or not taken for 3 weeks then 7 was taken in 3 or 4 hours. How can a blood test toxicology tell the difference? Will the blood test show none was taken for 3 weeks when it’s usually taken 3 times daily? Please explain the difference to me, he was mentally ill when this was done in this manner. Thanks
    • Anonymous
      I’m way late but for people that want the answer to this question yes they can tell if you are taking more or less of your meds if they order the test for it. It’s not something they regularly do but they can do it. I’m not sure if it’ll show that you didn’t take any for 3 weeks but if your doctor felt like you weren’t taking your meds probably they could totally test for it.
  • Andrew
    I took a .5 mlgm Kpin on Wednesday, 2morrow is Monday and I have a urine test. I haven’t taken anything else in years and I pee a lot. Will I pass??