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How Long Does Klonopin Stay in Your System?

How long does klonopin stay in your system? Read on to learn about the effects of Klonopin and how it is a widely prescribed medication.

How long does klonopin stay in your system

Article Contents

What is Klonopin (Clonazepam)?

Klonopin is the brand name for the drug clonazepam. It is a long-lasting prescription sedative approved by the Food and Drug Administration (FDA) for treatment programs for patients with panic and seizure disorders. Medical providers may also prescribe Klonopin “off label” (a use not approved by the FDA) to treat essential tremor and tardive dyskinesia.

Klonopin, or clonazepam, is an FDA-approved benzodiazepine for treating panic and seizure disorders. Klonopin is classified as a benzodiazepine meaning the side effects of taking Klonopin are like those of other benzodiazepine drugs.

What Are the Effects of Klonopin?

Klonopin belongs to the benzodiazepine class of drugs, and the effects experienced when taking it to mimic those of other sedative medications like Xanax and Ativan. It is dangerous to mix Klonopin with other medications, especially opioids or other depressants such as alcohol or other benzodiazepines. Mixing drugs, or polydrug abuse, can lead to potentially life-threatening effects.

When taken as prescribed, Klonopin has several therapeutic benefits; however, clonazepam also has expected side effects, including irritability, problems with coordination, memory and concentration difficulties, appetite loss, nausea, dizziness, and fatigue. In some instances, severe side effects can occur with Klonopin use. These include difficulty breathing, reduced blood pressure, elevated heart rate, loss of consciousness, severe depression, and suicidal ideation.1

Dangers of Klonopin

On its own, Klonopin is not typically dangerous; however, its use is not without the risk of addiction or potential overdose. Recent data from the Centers for Disease Control and Prevention show benzodiazepines like Klonopin were involved in 17% of all drug overdose deaths between January 2019 and June 2020.


What is Klonopin Half-life?

The half-life of a drug is the timeframe your body requires to remove half of the drug from your system. The Klonopin half-life is very long compared to other drugs of the same class. Many benzodiazepines and most opioids have relatively short half-lives; however, Klonopin’s half-life ranges from 20 to 50 hours.
Based on the long half-life of Klonopin, it is reasonable to wonder, “how long does it take to get Klonopin out of your system?” Klonopin elimination time can vary widely. Some people may take up to 14 days to eliminate Klonopin from their bodies.

When Does Klonopin Peak?

Because the half-life of Klonopin is quite long, many people wonder how long does Klonopin last? How long does Klonopin take to work? Klonopin begins producing a calming effect within one to four hours, and the drug reaches peak effectiveness in approximately four hours. However, you may still feel Klonopin’s calming and sedating effects for several hours.

Factors that Influence the Stay of Klonopin in Your System

Several factors may influence how long clonazepam effects last and how long Klonopin stays in your system at detectable levels. These factors include age, gender, dosage, frequency of use, and duration of use. 4


The younger you are, the more quickly your body can metabolize (process and eliminate) Klonopin. Our metabolism rates tend to slow as we age.


Biological gender may play a role in the speed of metabolism and, therefore, how quickly the body processes Klonopin. Additionally, someone with a higher body mass index or BMI may process Klonopin slower because the drug will stick to fat cells while being metabolized.

Dosage (Low vs. High)

Higher doses of Klonopin will take longer to eliminate than smaller doses. Because Klonopin is a long-acting benzodiazepine, the more you have in your body at any given time, the longer it will remain detectable through various drug tests.

Frequency and Duration Of Use

With consistent use, as you would if prescribed Klonopin for a medical condition, levels of Klonopin can build up in your body. The longer and more often you take the drug, the more likely you are to develop a tolerance to its effects. Tolerance can also increase the amount you take with any given dose. Both frequency and duration of Klonopin use affect how long it takes your body to eliminate the drug.

How Long Does Klonopin Stay in Your System?

Medical providers have several test options to test for the presence of Klonopin. Various types of Klonopin drug tests help to answer the question adequately, how long does Klonopin stay in your system?

Stay of Klonopin in the Body

How long does Klonopin stay in your system? Klonopin is a long-acting benzodiazepine. It takes your body up to; however, the amount of time various tests can detect Klonopin in your body depends on the type of test and the factors mentioned above.

Stay of Klonopin in Hair

Studies suggest Klonopin remains detectable in your hair up to 28 days after your last dose. 5

How Long Does Klonopin Stay in Your Urine?

It can be difficult to accurately detect Klonopin using a urine test. Some tests may be able to show the drug is present in your body but not how much. Research suggests the average clonazepam urine detection time is between 21 and 30 days. 6

Stay of Klonopin in Saliva

Klonopin saliva tests can detect the presence of the drug in your body up to six days after the last dose. 7

How Long Does Klonopin Stay in Your Blood?

Klonopin remains detectable in your blood for several days. Also, due to its rapid onset, it is possible to detect the presence of Klonopin in your body through a blood test shortly after taking the drug.

Unfortunately, very few reliable studies provide a solid timeframe for how long you can detect Klonopin in your blood. 8

How to Detox from Klonopin

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Both physical and psychological dependence on Klonopin can occur even when prescribed as prescribed. Studies suggest you can develop a physical dependence on Klonopin after two weeks of daily use, even if using it precisely as directed. 9

If you have been regularly using clonazepam, you must speak to your provider if you are ready to stop using it. If you abruptly stop taking your regular dose, unpleasant and potentially dangerous side effects can occur. A medical detox program like ours at Iris Healing® can help you slowly and safely taper off Klonopin under medical supervision.

Klonopin Withdrawal Risks

Stopping Klonopin “cold turkey” can cause various withdrawal effects, some of which can be dangerous. Examples of these include seizures, hallucinations, tremors, stomach cramps, and thoughts of suicide. Klonopin is a schedule IV controlled substance, and its use is not without the risk of misuse and addiction. Approximately 17% of people with prescriptions for benzodiazepines like Klonopin misuse them.

Treatment for Addiction at Iris Healing®

When you are addicted to Klonopin, getting help from a formal detox and addiction treatment program is crucial. The best treatment programs offer vital medical and mental health support to ensure you can safely overcome Klonopin addiction.

Our caring, experienced treatment professionals can help you take the first steps towards detoxing and healing. Contact us today to learn how to get treatment for Klonopin addiction at Iris Healing®.

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