You should never take more of your Klonopin or take it in a different way than intended by your doctor to try to speed up the onset of effects. Doing so can increase your risk of complications and overdose and may cause the medication to work differently than intended.
Onset of Effects
Klonopin is a brand name for the intermediate-acting benzodiazepine clonazepam. These drugs are prescribed to treat seizure disorders and panic attacks by decreasing activity in the brain.[1]
When taken as prescribed, Klonopin will reach its peak concentrations in the blood within one to four hours, though you will likely feel some of the calming effects earlier than that.[2] Experts say clonazepam takes about 20 to 60 minutes to start working in most people.[6] The effects of clonazepam may last up to 12 hours.
Klonopin is often called a long-acting benzodiazepine but in reality, the term intermediate-acting is arguably more accurate.[3]
Factors That Impact Clonazepam Absorption
The method by which a drug is taken can significantly impact the speed of absorption.
Klonopin is generally taken orally, which is one of the slowest paths of absorption. Note that “slow” doesn’t mean ineffective. It is deliberately prescribed orally to produce the best results in patients who take it as prescribed.
If the drug is instead snorted, as some people who misuse the medication take it, absorption will be faster. This is generally done to produce a more intense effect, resulting in a “high.” This type of drug misuse can be dangerous, increasing one’s risk for various complications, including these:[1,2]
- Profound respiratory depression
- Unconsciousness or coma
- Severe confusion
- Klonopin dependence
- Addiction to Klonopin
Some health conditions can also affect drug absorption, such as some GI diseases, as can some drugs. This is why it’s important to talk openly with your doctor about your health and any drugs you’re taking when being prescribed any medication. The doctor needs to have an accurate understanding of how your body is likely to react to Klonopin and if any dangerous interactions might occur.
Your individual metabolism matters too. Some people are quick metabolizers of drugs, meaning that drugs move out of the body very quickly before people even notice them. If you’re someone like this, you may not notice your dose at all, even though it’s within your body.[7]
How Does Klonopin Work?
The brain uses gamma-aminobutyric acid (GABA) to pass messages from one cell to another. Klonopin works by altering GABA levels, so the brain can’t trade messages as quickly. The result is a calm sensation and relaxed muscles.
Klonopin isn’t the only benzodiazepine drug available. There are several of them, including clonazepam, diazepam, and lorazepam. All of them work by altering GABA, as we have described.
Some benzodiazepines work faster than Klonopin. For example, midazolam and diazepam are distributed in the body very quickly, so they work quicker than other drugs in the class.[8]
How Long Does It Last?
Klonopin has a half-life of about 30 to 40 hours, which is how long it takes the body to eliminate around 50 percent of the drug.
Within about four to five half-lives, or 120 to 200 hours, you can expect at least 95 percent of the drug to be eliminated from the body, assuming the body is able to process the drug normally.[2]
Know that these are simple estimates, and your timeframes may differ. For example, some people use “dose stacking” to keep a Klonopin high going. They take another dose when the first hasn’t yet worn off. A technique like this could extend how long the drug stays in your system.
Klonopin (Clonazepam) Dosages
Klonopin dosages will depend on why the drug is being taken and can be highly variable among children, as their bodies are more varied than those of adults.
Typical doses include the following:[4]
| Condition | Typical Dose | |
| Epilepsy (Adult Dosages) | 1 mg taken at night, increasing to 4-8 mg over the next 2-4 weeks | |
| Involuntary Muscle Spasms | 1-2 mg each day | |
| Restless Legs Syndrome | 500 micrograms to 2 mg each day | |
| Children with Epilepsy | Dosages vary significantly for children, following similar increases over 2-4 week periods |
Klonopin Prescribing Info
Dosing varies, but patients are typically started on a small dose, with their dose raised if the drug doesn’t have the desired effect. (1)
In some cases, it can take a few days to a few weeks for Klonopin to fully take effect depending on why it’s being used, such as if it is used to reduce seizures.
When possible, it is only prescribed in the short term, as long-term use can cause a person to develop physical dependence and increase the risk of engaging in drug misuse or becoming addicted to the drug. (1)
- Clonazepam. (May 2021). U.S. National Library of Medicine.
- Klonopin Tablets (clonazepam) (October 2013). U.S. Food and Drug Administration.
- KLONOPIN TABLETS (clonazepam). (October 2013). U.S. Food and Drug Administration.
- Benzodiazepines in Older Adults: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines [Internet] (January 2011). McIntosh B, Clark M, Spry C. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2011 Jan. Table 1, Pharmacokinetic Classification of Benzodiazepines Available in Canada.
- How and when to take clonazepam. (January 2023). United Kingdom National Health Service.
- Clonazepam: 7 Things You Should Know. (February 2023). Drugs.com.
- Cytochrome P450 2C19 Rapid Metabolizer. Children’s Minnesota.
- Benzodiazepines. (January 2023). StatPearls.
