How Long Does Klonopin Stay In Your System?
In our latest question and answer, our pharmacist discusses how long Klonopin (clonazepam) stays in your system and is detectable in the urine.
I don't take Klonopin ever but on Sunday, January 1st, 2023, I had a sudden loss in my immediate family. My sister gave me a Klonopin tablet to help with anxiety. I got a call this morning saying I have a job interview this Wednesday, which will only be 3 days away. Will I be able to pass a urine test? I've heard they don't allow Klonopin use with no excuses. Thank you.
Jan 02, 2023- Klonopin is a long-acting benzodiazepine with a half-life of 30-40 hours that is typically detectable in urine for at least 5-10 days after a single dose.
- Regular users of Klonopin may test positive for much longer periods, sometimes up to 30 days, because the drug accumulates in the body over time.
- Several factors affect how long Klonopin stays in your system, including age, liver and kidney function, hydration level, and whether the test is looking for the drug itself or its metabolites.
Answer
Thanks so much for reaching out. First and foremost, I'm so sorry to hear about the loss of a family member. My thoughts are with you.
In regard to Klonopin (clonazepam), it is, unfortunately in your case, a long-acting benzodiazepine, and stays in your system for some time. It is likely to be detectable in your urine for at least 5-10 days, and longer for those who take the drug consistently.
Klonopin Has A Long Half-Life
The half-life of a drug is the amount of time it takes the body to metabolize and eliminate 50% of a drug. As a general rule of thumb, it takes around 5-6 half-lives for a drug to no longer be detectable on a urine drug screening.
While sources do vary somewhat, the reported half-life of Klonopin is 30-40 hours, with some sources reporting up to 60 hours.
If we take the conservative end, a half-life of 30 hours, it would take about 150 hours, a little over 6 days, to be completely eliminated and not show up on a urine drug test.
Some studies have shown as well that Klonopin is detectable for much longer in individuals who consistently take the drug, up to 30 days sometimes.
Factors That Influence How Long Klonopin Stays In Your System
As mentioned, 5-10 days is a general timeframe for how long Klonopin is detectable in the urine for someone who doesn't take it consistently.
However, there are many factors that will influence this time frame, including:
- Your age
- Your liver and kidney function
- How hydrated you are
- How long you have been taking the drug
- What the urine screen is testing for
In regard to this last point here, there are several different ways a urine test can detect clonazepam. Sometimes tests look for the parent drug (clonazepam in this case), while others test for a metabolite of clonazepam, 7-aminoclonazepam. This metabolite generally lasts a little longer in your system than clonazepam.
In fact, one study found that all 10 individuals who were tested 14 days after taking a 3mg dose of clonazepam still tested positive on a urine drug test:
The urine from every subject was still positive for 7-ACLO [7-aminoclonazepam] 14 days after administration of the drug. Eight of the ten volunteers had measurable amounts of the metabolite 21 days after administration. One volunteer was still positive 28 days after administration.
So, overall it's tough to give a definitive amount of time a urine drug test will come back positive after taking a dose, but at least we have a general idea that it's going to be for around 5-10 days, and for a longer period of time in some individuals, or in those getting specific tests.
Final Words
Again, I'm sorry about your loss and I hope this answer provided you with the information you were looking for.
References & sources
- Elimination of 7-aminoclonazepam in urine after a single dose of clonazepam — PubMed
- Klonopin Prescribing Information — PubMed
- Detection Times of Diazepam, Clonazepam, and Alprazolam in Oral Fluid Collected From Patients Admitted to Detoxification, After High and Repeated Drug Intake — PubMed
- Comparison of clonazepam compliance by measurement of urinary concentration by immunoassay and LC-MS/MS in pain management population — PubMed
- Prolonged excretion of 7-aminoclonazepam in urine after repeated ingestion of clonazepam: a case report — PubMed
Glossary — Terms in This Answer
- Benzodiazepine
- A class of prescription drugs that slow down brain activity and are commonly used to treat anxiety, seizures, and sleep problems.
- Half-life
- The amount of time it takes for the body to break down and eliminate half of a drug from your system.
- Metabolize
- The process by which your body breaks down a drug into different substances so it can be eliminated.
- Urine drug screening
- A test that analyzes urine to detect the presence of drugs or their remains in your body.
- Parent drug
- The original form of a medication as it was taken, before your body breaks it down into other substances.
- Metabolite
- A substance created when your body breaks down a drug into different chemical forms.
- Clonazepam
- The generic name for Klonopin, a benzodiazepine medication used to treat anxiety and seizures.
- 7-aminoclonazepam
- A breakdown product of clonazepam that forms when your body processes the drug and can be detected in urine tests.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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