Zopiclone - PsychonautWiki


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Fatal overdose may occur when GABAergic substances are combined with other depressants such as opiates, benzodiazepines, barbiturates, gabapentinoids, thienodiazepines or alcohol.[1]

It is strongly discouraged to combine these substances, particularly in common to heavy doses.

Summary sheet: Zopiclone
Chemical Nomenclature
Common names Zimovane, Imovane
Substitutive name Zopiclone
Systematic name (RS)-6-(5-Chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-yl 4-methylpiperazine-1-carboxylate
Class Membership
Psychoactive class Depressant / Hallucinogen
Chemical class Cyclopyrrolone
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.

Bioavailability 52 - 59%[citation needed]
Threshold 2 mg
Light 3.5 - 5 mg
Common 5 - 7.5 mg
Strong 7.5 - 15 mg
Heavy 15 mg +
Total 3.5 - 9 hours
Onset 10 - 30 minutes
Peak 3 - 4 hours

DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.


Zopiclone (also known by the trade names Zimovane and Imovane) is a non-benzodiazepine hypnotic substance of the cyclopyrrolone class. It belongs to a family of substances colloquially known as "Z-drugs", which includes zaleplon (Sonata) and zolpidem (Ambien and AmbienCR). The mechanism of action is benzodiazepine-like GABA binding activity.

It is primarily used in the treatment of insomnia due to its heavy sedative effects.[citation needed]

While "Z-drugs" were initially thought to have less misuse potential than benzodiazepines, this appraisal has shifted somewhat in the last few years as a number of cases of addiction and habituation have been observed. Zopiclone, like all "Z-drugs", is recommended to be taken on a short-term basis -- usually a week or less.[2] Daily or continuous use of the drug is usually not advised.[3]

It is highly advised to use harm reduction practices if using this substance.


Zopiclone is a hypnotic nonbenzodiazepine drug of the cyclopyrrolone class. Zopiclone and its closely related dextrorotatory S-stereoisomer zopiclone (Lunesta) are the most popular and available cyclopyrrolone drugs. This class of drugs is named for having a pyrrolone core, a five-membered ring with a nitrogen constituent (pyrrole) and a ketone group (-one).

The ketone group found in zopiclone is located at R5 of the pyrrolone ring. Zopiclone contains four nitrogenous rings including pyrrolone. Fused to the pyrrolone core is a pyrazine ring, a six-membered aromatic ring with two nitrogen substituents. The two rings are fused at R3 and R4. This bicylic core is called a pyrollopyrazine. Bound to the nitrogen group of the pyrrolone at R6 is a substituted pyridine ring. Pyridine is six-membered unsaturated ring with one nitrogen group. The pyridine ring of zopiclone is substituted at R5 with a chlorine group.

The final ring of zopiclone is a piperazine ring. Piperazine is a six-membered saturated ring with two nitrogen constituents; in this case, it is substituted at R4 with a methyl group. This piperazine ring is connected to the pyrrolone core of zopiclone at R7 through a carboxylate group.

Zopiclone may be measured in blood, plasma, or urine by chromatographic methods. Plasma concentrations are typically less than 100 μg/l during therapeutic use, but frequently exceed 100 μg/l in automotive vehicle operators arrested for impaired driving ability and may exceed 1000 μg/l in acutely poisoned patients. Post mortem blood concentrations are usually in a range of 0.4-3.9 mg/l in victims of fatal acute overdose.[4]


Zopiclone shares an almost identical pharmacological profile to benzodiazepines despite differences in structure. The mechanism of action works by binding to the same site as benzodiazepines and acts as a full agonist, which in turn positively modulates benzodiazepine-sensitive GABAA receptors and enhances GABA binding at the GABAA receptors to produce zopiclone's subjective effects.[citation needed]

Since GABA functions as the brain's predominant inhibitory neurotransmitter, this activation of receptors results in the sedative and anxiolytic effects of zopiclone.[citation needed] In addition to zopiclone's benzodiazepine pharmacological properties, it also has some barbiturate-like properties.

Additionally, it (along with desmethylzopiclone) is a noncompetitive antagonist at nicotinic acetylcholine receptor [5]. This could be the cause of deliriant like effects.

The metabolite of zopiclone called desmethylzopiclone is also pharmacologically active, although it has predominately anxiolytic properties. One study found some slight selectivity for zopiclone on α1 and α5 subunits,[6] although it is regarded as being unselective in its binding to α1, α2, α3, and α5 GABAA benzodiazepine receptor complexes.

Desmethylzopiclone has been found to have partial agonist properties, unlike the parent drug zopiclone, which is a full agonist.[7] The mechanism of action of zopiclone is similar to benzodiazepines, with similar effects on locomotor activity and on dopamine and serotonin turnover.

Subjective effects

In comparison to other substances of a similar nature such as benzodiazepines, zopiclone is commonly reported to present significantly more amnesic and disinhibiting effects in a manner similar to alcohol. Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

Visual effects

Cognitive effects

Auditory effects

Experience reports

Anecdotal reports which describe the effects of this compound within our experience index include:

Additional experience reports can be found here:

Toxicity and harm potential


This toxicity and harm potential section is a stub.

As a result, it may contain incomplete or even dangerously wrong information! You can help by expanding upon or correcting it.
Note: Always conduct independent research and use harm reduction practices if using this substance.

Zopiclone is generally thought to have a low toxicity relative to dose. However, it is potentially lethal when mixed with depressants like benzodiazepines, alcohol or opioids. When combined with one or several of these substances the already existing chance of a having a "black-out" is significantly increased, leaving the user with very little to no memory of the events that occurred whilst under the influence of zopiclone alone or combined with most other CNS depressants.

Some users have reported taking zopiclone in combination with alcohol in an attempt to treat hangovers with varying degrees of success.

It is strongly recommended that one use harm reduction practices when using this substance.

Dependence and abuse potential

Zopiclone is extremely physically and psychologically addictive. This compound may have an even greater addictive potential than benzodiazepines. Tolerance will develop to the sedative-hypnotic effects within a couple of weeks of daily use. After cessation, the tolerance returns to baseline in 7 - 14 days. Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing, and may necessitate a gradual dose reduction.

Zopiclone presents cross-tolerance with all benzodiazepines, meaning that after its consumption benzodiazepines and most other GABAgenic depressants will have a reduced effect.[8]

Dangerous interactions

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

Legal status


This legality section is a stub.

As such, it may contain incomplete or wrong information. You can help by expanding it.

  • Canada: Zopiclone is available by prescription only in Canada.[9]
  • Germany: Zopiclone is a prescription medicine, according to Anlage 1 AMVV[10]
  • Norway: Zopiclone is available by prescription in Norway.[citation needed]
  • Switzerland: Zopiclone is listed as a "Abgabekategorie B" pharmaceutical, which generally requires a prescription.[citation needed]

See also

External links


  1. Risks of Combining Depressants - TripSit 
  2. http://www.nice.org.uk/nicemedia/pdf/TA077publicinfoenglish.pdf
  3. Kleijn, E. van der (1989). "Effects of zopiclone and temazepam on sleep, behaviour and mood during the day". European Journal of Clinical Pharmacology. 36 (3): 247–251. doi:10.1007/BF00558155. ISSN 0031-6970. 
  4. Kratzsch, C., Tenberken, O., Peters, F. T., Weber, A. A., Kraemer, T., Maurer, H. H. (August 2004). "Screening, library-assisted identification and validated quantification of 23 benzodiazepines, flumazenil, zaleplone, zolpidem and zopiclone in plasma by liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization". Journal of Mass Spectrometry. 39 (8): 856–872. doi:10.1002/jms.599. ISSN 1076-5174. 
  5. Fleck, M. W. (August 2002). "Molecular actions of (S)-desmethylzopiclone (SEP-174559), an anxiolytic metabolite of zopiclone". The Journal of Pharmacology and Experimental Therapeutics. 302 (2): 612–618. doi:10.1124/jpet.102.033886. ISSN 0022-3565. 
  6. John R. Atack (August 2003). "Anxioselective compounds acting at the GABA(A) receptor benzodiazepine binding site". Journal of CNS and Neurological Disorders. 2 (4): 213–332. doi:10.2174/1568007033482841. ISSN 0022-3565. 
  7. Atack, J. R. "Anxioselective Compounds Acting at the GABAA Receptor Benzodiazepine Binding Site". Current Drug Targets - CNS & Neurological Disorders. 2 (4): 213–232. 
  8. Zopiclone and triazolam in insomnia associated with generalized anxiety disorder. If zopiclone has been taken for more than a few weeks, then the medication should be gradually reduced or preferably crossed over to an equivalent dose of diazepam (Valium) which has a much longer half-life, making withdrawal easier. One should then gradually taper the dose over a period of several months to avoid extremely severe and unpleasant withdrawal symptoms which can last up to two years after withdrawal if the withdrawal is done too abruptly. http://www.benzo.org.uk/manual/
  9. https://ccsa.ca/sites/default/files/2019-04/CCSA-Canadian-Drug-Summary-Prescription-Sedatives-2017-en.pdf
  10. AMVV - Verordnung über die Verschreibungspflicht von Arzneimitteln