Klonopin (Clonazepam) at a glance: schedule, half-life, and class
- Generic name
- Clonazepam
- Brand names
- Klonopin
- Drug class
- Long-acting benzodiazepine
- US legal status
- Schedule IV, prescription only
- Approved uses
- Panic disorder; seizure disorders (Lennox-Gastaut, akinetic, myoclonic, absence)
- Forms
- Tablets, orally disintegrating tablets
- Onset
- 20 to 60 minutes
- Half-life
- 30 to 40 hours
- Broken down by
- CYP3A4
- FDA boxed warnings
- Use with opioids; misuse and addiction; dependence and withdrawal
Klonopin uses: what clonazepam is prescribed for
Clonazepam is approved for panic disorder with or without agoraphobia, and alone or as an add-on for several seizure types, including Lennox-Gastaut syndrome and absence seizures.[1]
Off-label, it is sometimes used for REM sleep behavior disorder, restless legs, and akathisia.
Klonopin dosage: how clonazepam is usually prescribed
The figures below come from the FDA-approved label and describe how prescribers typically use clonazepam. They are not personal dosing advice. A prescriber sets the dose for each person and adjusts it over time.[1]
| Condition | Typical adult dose | Label guidance |
|---|---|---|
| Panic disorder | 0.25 mg twice a day, raised to 1 mg a day after 3 days | Maximum 4 mg a day |
| Seizure disorders | No more than 1.5 mg a day in three doses to start | Raised 0.5 to 1 mg every 3 days; maximum 20 mg a day |
Klonopin (clonazepam) side effects and risks
FDA boxed warnings
- Taking benzodiazepines with opioids can cause profound sedation, slowed breathing, coma, and death.[2]
- Benzodiazepines can be misused and can lead to addiction, which raises the risk of overdose and death.[3]
- Regular use can cause physical dependence. Stopping suddenly or cutting the dose quickly can cause withdrawal reactions, including seizures, that can be life-threatening.[3]
Common side effects include drowsiness, dizziness, poor coordination, fatigue, depression, and memory problems.[1]
Suicidal thoughts: like other antiseizure medicines, clonazepam carries a warning about a small increase in suicidal thoughts and behavior.[1]
Klonopin interactions: what not to mix with clonazepam
Choose what it would be combined with:
| Combined with | What happens | Label guidance |
|---|---|---|
| Opioids (oxycodone, fentanyl, codeine) | Slowed breathing, coma, death | Boxed warning; avoid unless no alternative |
| Alcohol | Stronger sedation and slowed breathing | Avoid |
| Other sedatives, sleep medicines, gabapentinoids | Additive drowsiness and impaired coordination | Use caution |
| Strong CYP3A4 inhibitors (ketoconazole, clarithromycin) | Raise clonazepam levels | Use caution |
| Carbamazepine, phenytoin | Lower clonazepam levels | Monitor seizure control |
This is not a full list. A pharmacist can check a complete medication list, including supplements and over-the-counter products.[1]
Klonopin overdose: signs of clonazepam overdose and what to do
Clonazepam overdose causes deep drowsiness, confusion, poor coordination, slowed reflexes, and coma. With opioids or alcohol, breathing can stop.[1]
If someone may have overdosed
- Call 911 if the person is unresponsive, hard to wake, or breathing slowly.
- For advice when the person is awake and stable, call Poison Help at 1-800-222-1222 (US, free, 24 hours).
- If opioids could be involved, including pills not from a pharmacy, give naloxone if you have it. Naloxone does not reverse clonazepam, but it will not harm the person.
- Stay with the person and place them on their side if they are drowsy or vomiting.
Klonopin withdrawal timeline: how long clonazepam withdrawal lasts
People who take clonazepam regularly, even as prescribed, can become physically dependent within weeks. Its long half-life means withdrawal often begins a few days after the last dose.[3]
- Days 2 to 5Symptoms beginRebound anxiety, insomnia, restlessness, sweating, and tremor.
- Weeks 1 to 4Acute withdrawalPanic, irritability, muscle pain, nausea, sensitivity to light and sound, and in severe cases seizures or delirium.
- MonthsProtracted symptoms in some peopleA minority have lingering anxiety, poor sleep, low mood, or tingling that can last weeks to more than 12 months.
Warning: Stopping clonazepam abruptly after regular use can cause seizures. The dose should be reduced gradually under the care of a prescriber.
The label advises lowering the dose by 0.125 mg twice a day every three days for panic disorder, but many people need a much slower taper. In people with epilepsy, stopping suddenly can trigger continuous seizures (status epilepticus).[4]
How to get prescribed Klonopin (clonazepam) legally in the US
In the United States, clonazepam is a Schedule IV controlled substance. The only legal way to get it is with a prescription from a clinician registered with the Drug Enforcement Administration (DEA), filled by a licensed pharmacy. Depending on state law, that can be a physician, nurse practitioner, or physician assistant.[5]
- Refills: a Schedule IV prescription can be refilled up to five times within six months of the date it was written. After that, a new prescription is needed.[6]
- Telehealth: federal flexibilities let DEA-registered clinicians prescribe Schedule II to V medicines after a telemedicine visit, without a prior in-person exam, through December 31, 2026. A permanent DEA rule was under final review in late 2026. State rules can be stricter.[7]
- Monitoring: prescribers and pharmacists in most states check a prescription drug monitoring program, a database of controlled-substance prescriptions, before prescribing or dispensing.
- Pharmacies: a legitimate pharmacy always requires a valid prescription, has a licensed pharmacist available, and is licensed in the state it ships to. The FDA's BeSafeRx tool and the NABP's safe pharmacy list help confirm a pharmacy is real.[8][9]
- Cost: generic clonazepam is inexpensive and widely covered.
Warning: Pills sold as Klonopin outside a pharmacy are often counterfeit. The DEA reports that fake pills frequently contain fentanyl or methamphetamine, and they cannot be told apart by appearance.[10]
Traveling: keep the medicine in its original pharmacy container and carry a copy of the prescription. Check the rules of the destination country before travel, because many countries restrict controlled medicines or require a permit.
Can you order Klonopin (clonazepam) online legally?
Yes, but only with a valid prescription and only from a pharmacy licensed in your state. Many licensed pharmacies, including mail-order pharmacies run by insurers, fill clonazepam prescriptions online and ship them. Buying clonazepam from a website that does not require a prescription is illegal, and the product is often fake.[8][10]
- See a licensed clinicianA clinician evaluates you in person or by telemedicine and decides whether clonazepam is appropriate.
- The prescription goes to a pharmacyPrescriptions for controlled medicines are usually sent electronically, straight from the prescriber to the pharmacy you choose.
- The pharmacy checks and fills itA pharmacist verifies the prescription and your identity, then dispenses the medicine in person or by mail.
Signs that an online seller is illegal:
- It sells clonazepam with no prescription, or after only a short online questionnaire.
- It takes orders through social media, messaging apps, or email.
- It asks for payment in cryptocurrency, gift cards, or money transfers.
- It has no US street address, no state pharmacy license, and no pharmacist to speak to.
- Its prices are far below those of ordinary pharmacies, or it ships from another country.
The FDA's BeSafeRx tool links to each state's license lookup, and the National Association of Boards of Pharmacy lists verified online pharmacies.[8][9]
Klonopin price: how much does Klonopin (clonazepam) cost without insurance?
Generic clonazepam is inexpensive and widely covered.
What you pay depends on the strength, the number of doses, your insurance plan, and the pharmacy. Cash prices for the same prescription can differ several times over between pharmacies in the same town, so check current prices before you fill it.
Ways to pay less, legally:
- Ask the prescriber whether a generic clonazepam is available. FDA-approved generics work the same way as the brand and usually cost much less.
- Compare cash prices between pharmacies before you fill the prescription.
- Use a free prescription discount card, such as GoodRx or SingleCare, when you pay cash. These cards cannot be combined with insurance on the same fill.
- For brand-name medicines, check the manufacturer's savings program or patient assistance program.
- Ask about a 90-day supply or your insurer's mail-order pharmacy, which often lowers the cost per dose when your prescriber agrees it is appropriate.
Warning: A price far below what licensed pharmacies charge, especially with no prescription required, is a strong sign of an illegal seller and counterfeit medicine.[8]
Is Klonopin legal? Clonazepam legal status in other countries
| Country | Status |
|---|---|
| United Kingdom | Class C; prescription only |
| Canada | Schedule IV (targeted substance); prescription only |
| Australia | Schedule 4 prescription medicine |
| International | Schedule IV of the 1971 Convention on Psychotropic Substances |
Laws change and differ in detail. Check current rules before carrying any controlled medicine across a border.[11]
Common questions about Klonopin (clonazepam)
Is clonazepam the same as Klonopin?
Yes. Klonopin is the brand name for clonazepam.
How long does Klonopin (clonazepam) stay in your system?
Its half-life is 30 to 40 hours, so it takes about a week to clear. Urine tests can detect it for 5 to 10 days or longer.
Is Klonopin (clonazepam) better than Xanax for panic disorder?
Clonazepam lasts longer, which avoids between-dose rebound anxiety. Both carry the same risks of dependence. Antidepressants and therapy are first-line treatments.
Can Klonopin (clonazepam) be stopped suddenly?
No. Stopping suddenly can cause severe withdrawal and, in people with epilepsy, prolonged seizures.
Can you buy Klonopin (clonazepam) without a prescription?
No. Klonopin (clonazepam) is a Schedule IV controlled substance in the US, so it is illegal to buy or possess it without a valid prescription. Websites and social media sellers that offer it without one are not legal pharmacies, and the DEA warns that pills sold this way are often counterfeit and can contain fentanyl. The legal route is a visit with a licensed clinician, in person or by telehealth, and a prescription filled at a state-licensed pharmacy. The FDA's BeSafeRx tool and the NABP's safe pharmacy list help confirm an online pharmacy is real.
Sources
- Klonopin (clonazepam) prescribing information. DailyMed, US National Library of Medicine.
- FDA warns about serious risks and death when combining opioid pain or cough medicines with benzodiazepines. US Food and Drug Administration, 2016.
- FDA requiring Boxed Warning updated to improve safe use of benzodiazepine drug class. US Food and Drug Administration, 2020.
- Joint Clinical Practice Guideline on Benzodiazepine Tapering. American Society of Addiction Medicine, 2025.
- Controlled Substance Schedules. DEA Diversion Control Division.
- 21 CFR 1306.22, Refilling of prescriptions (Schedules III and IV). Electronic Code of Federal Regulations.
- Prescribing controlled substances via telehealth. US Department of Health and Human Services.
- BeSafeRx: Your Source for Online Pharmacy Information. US Food and Drug Administration.
- Safe Pharmacy. National Association of Boards of Pharmacy.
- One Pill Can Kill. US Drug Enforcement Administration.
- International drug control conventions. United Nations Office on Drugs and Crime.
