Formal Name: 6-(2-chlorophenyl)-1-methyl-8-nitro-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine
CAS Number: 33887-02-4
Molecular Formula: C17H12ClN5O2
Formula Weight: 353.8
Purity: ≥98%
Formulation: A neat solid



Clonazolam is a benzodiazepine that was developed as a central nervous system depressant in the 1970s and has recently emerged as a drug of abuse. It potently antagonizes convulsions induced by thiosemicarbazide and pentobarbital (ED50s = 90 µg/kg for both agonists in mice). In vitro phase I metabolites of clonazolam, derived from human liver microsomes, have been described. This product is intended for forensic and research applications.
WARNING This product is not for human or veterinary use.

Clonazolam is a designer triazolobenzodiazepine first synthesized in the 1970s that has never been licensed for therapeutic use. Clonazolam first surfaced on the internet in 2014 as a drug of abuse. Cases of intoxication involving clonazolam have been identified since 2016 in Europe with a single case described in the US in 2017. It is typically found in tablet, capsule, pellet, blotter, or powder form. A 28-year-old man presented with somnolence to an emergency department after reportedly ingesting one-half of a 30 mL vial of liquid clonazolam he purchased from the internet. He had normal vital signs and had no distress on presentation. His laboratory tests were normal, and his mental status cleared during a 6-hour observation in the emergency department. Non-targeted analysis of the liquid using liquid chromatography-quadrupole time-of-flight mass spectrometry identified clonazolam (0.4 mg/mL) with no other pharmaceuticals. This is the second case of intentional clonazolam ingestion described in the United States, and is unique in that the substance was found in liquid form. Providers should be aware that clonazolam is available on the internet in liquid formulation, which may increase the risk of accidental overdose.

It, or 6-(2-chlorophenyl)-1-methyl-8-nitro 4H-[1,2,4]triazolo[4,3-α][1,4] benzodiazepine, is the triazolo-analogue of clonazepam and was first synthesized in 1971 (Figure 1) [1]. It has never been licensed for therapeutic use in any part of the world or by the US Food and Drug Administration (US FDA) [2–4]. It surfaced on the internet market in 2014 as a drug of abuse [4]. Limited data regarding clonazolam prevalence and clinical effects has become available via the National Poison Data System (NPDS) and STRIDA project in Sweden [2,5]. Specific information regarding characteristics of intoxication is limited. We present a case of acute intoxication in a male patient who ingested a concentrated liquid solution of clonazolam.

We evaluated the contents of the vial using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) (Agilent LC1260-QTOF/MS 6550, Agilent technologies, Santa Clara, CA). We identified clonazolam at a concentration of 0.4 mg/mL without other pharmaceuticals (Figure 3). LC-QTOF/MS does not measure ethyl alcohol nor propylene glycol. The 30 mL vial contained an estimated 12 mg of clonazolam – an equivalent of 30–60 (0.2–0.4 mg) doses.

This case report describes a patient who ingested clonazolam and presented with a sedative-hypnotic toxidrome that resolved within a few hours without complication. The patient’s course appears typical compared to the cohort of 50 cases described by the NPDS review. The largest percentage of those cases exhibited minor effects (45%) and 68% experienced sedation/lethargy. Duration of effects was typically 8–24 hours (46%) or 2–8 hours (28%). The largest percentage of patients were treated and released from the ED (36%). There were zero deaths, however ten of the fifty patients were admitted to a critical care unit and three required intubation.

It is a potent, illicit benzodiazepine that is available in concentrated liquid form. The toxic effects are similar to those of other benzodiazepines.

Additional information


1000g, 100g, 10g, 250g, 500g, 50g


There are no reviews yet.

Be the first to review “Clonazolam”

Your email address will not be published.