Zopiclone

updated

What is Zopiclone?

Zopiclone is authorized for short-term insomnia in the UK and has been available in the EU since the mid-1980s, and it is marketed in Canada. No FDA-approved zopiclone product was located; the US sells its S-enantiomer, eszopiclone, as LUNESTA.

Zopiclone has been available in the EU as an insomnia treatment since the mid-1980s, is authorized in the UK and marketed in Canada, and no FDA-approved zopiclone product was located on 9 October 2026. A network meta-analysis supports short-term efficacy over placebo, but on-road studies show next-morning driving impairment larger than at a 0.05% blood alcohol level. A PubMed search found no trial of zopiclone for sleep disrupted by stimulants.

Hypnotic (racemic zopiclone)

  • EMA states zopiclone has been available in the EU as an insomnia treatment since the mid-1980s; EU zopiclone products are not centrally authorized, and no FDA application or label for zopiclone was located on 9 October 2026.
  • A network meta-analysis of 154 double-blind randomized trials (44,089 participants) found zopiclone more efficacious than placebo for acute insomnia, with more dropouts due to adverse events than placebo (OR 2.00) and eszopiclone (OR 1.82).
  • A review of eight on-road studies found zopiclone 7.5 mg at bedtime raised the standard deviation of lateral position by an average of 3.0 cm in 191 healthy volunteers, against a 2.4 cm rise at a blood alcohol concentration of 0.05%.
  • Crash studies are mixed: higher risk on days of use in Tayside (short-half-life hypnotics there were all zopiclone), a higher rate for zopiclone and zolpidem combined in Norway, and no association for zopiclone in France.
  • In 12 athletes, tests 10 hours after zopiclone showed no significant change in sprint, agility, VO2max or treadmill time, and loprazolam produced more reported hangover (8 of 11 versus 3 of 11).
  • A PubMed search on 9 October 2026 for zopiclone with stimulant terms returned 61 records, and none tested zopiclone for sleep disrupted by stimulants.

Where is zopiclone approved, and for what?

Zopiclone is authorized for short-term insomnia in the UK and has been available in the EU since the mid-1980s, and it is marketed in Canada. No FDA-approved zopiclone product was located; the US sells its S-enantiomer, eszopiclone, as LUNESTA.

EMA states that zopiclone has been available in the EU as a treatment for insomnia since the mid-1980s and describes eszopiclone as a purified form of one of zopiclone's two enantiomers. EMA's centrally authorized medicines data list no zopiclone product on 9 October 2026, so EU zopiclone products are not centrally authorized. The UK Zimovane summary of product characteristics (text revised 11 February 2026) indicates zopiclone for short-term treatment of insomnia in adults.

Health Canada's Drug Product Database lists IMOVANE 7.5 mg oral tablets (DIN 01926799, Sanofi-Aventis Canada) as marketed. A 5 mg IMOVANE tablet (DIN 02216167) is listed as cancelled post-market on 24 May 2022.

openFDA Drugs@FDA queries for zopiclone returned no application on 9 October 2026, and a DailyMed search returned no zopiclone label. This supports only a dated, US-scoped statement. The S-enantiomer eszopiclone was approved as LUNESTA under NDA 021476 on 15 December 2004, with generic applications from 2011. CHMP gave Lunivia (eszopiclone) a positive opinion for insomnia but concluded that eszopiclone could not be considered a new active substance, and the company withdrew the application on 13 May 2009.

Zopiclone is a racemate (C17H17ClN6O3, 388.8 g/mol, CAS 43200-80-2). Eszopiclone has the same formula and weight (CAS 138729-47-2). Data for one should not be carried over to the other without saying so, and supplier material sold as zopiclone has not been compared with either record.

EMA: zopiclone in the EU since the mid-1980s; Lunivia withdrawn 13 May 2009

Regulatory record

European Medicines Agency. Lunivia (eszopiclone), withdrawn application record. EMA lists no centrally authorized zopiclone product.

EMA states that zopiclone has been available in the EU as a treatment for insomnia since the mid-1980s and describes eszopiclone as a purified form of one of zopiclone's two enantiomers. CHMP gave Lunivia (eszopiclone) a positive opinion for insomnia but concluded that eszopiclone could not be considered a new active substance; the company withdrew the application on 13 May 2009. EMA's centrally authorized medicines data list no zopiclone product (read 9 October 2026), so EU zopiclone products are not centrally authorized.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Regulatory history from the mid-1980s to 2009
Study design
Official EMA record
Funding
not stated in the source

The record is about eszopiclone's withdrawn application and describes zopiclone's EU history. EU zopiclone products are authorized nationally, not centrally.

Read the original source
UK Zimovane SmPC, text revised 11 February 2026: indication, warnings, PK

Official label

electronic Medicines Compendium (medicines.org.uk). Zimovane film-coated tablets, summary of product characteristics, text revised 11 February 2026. Product 2855.

The summary of product characteristics indicates zopiclone for short-term treatment of insomnia in adults and limits treatment to the short term. It is contraindicated in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common. Peak levels come within 1.5 to 2 hours, the elimination half-life is about 5 hours, metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

Participants / model
Adults with insomnia; label PK participants
Treatment
Zimovane film-coated oral tablets
Follow-up
Text revised 11 February 2026
Study design
Official UK summary of product characteristics
Funding
not stated in the source

A UK label, not an FDA label. Dosing details are left out of this page.

Read the original source
Health Canada: IMOVANE 7.5 mg marketed; 5 mg cancelled post-market 24 May 2022

Regulatory record

Health Canada. Drug Product Database status record for IMOVANE oral tablets (DIN 01926799, DIN 02216167), read through the database API.

Health Canada's Drug Product Database lists IMOVANE 7.5 mg oral tablets (DIN 01926799, Sanofi-Aventis Canada) as marketed. A 5 mg IMOVANE tablet (DIN 02216167) is listed as cancelled post-market on 24 May 2022.

Participants / model
Not a clinical population
Treatment
Oral zopiclone tablets
Follow-up
Status as read on 9 October 2026
Study design
Official regulator database record
Funding
not stated in the source

The Canadian status comes from the Drug Product Database API record, not a product monograph.

Read the original source
openFDA, 9 October 2026: no zopiclone application; eszopiclone approved 2004

Regulatory record

U.S. Food and Drug Administration. openFDA Drugs@FDA queries for zopiclone by brand or generic name and by active ingredient, run on 9 October 2026, with a DailyMed label search.

openFDA Drugs@FDA queries for zopiclone, by brand or generic name and by active ingredient, returned no application on 9 October 2026, and a DailyMed search returned no zopiclone label. The S-enantiomer eszopiclone was approved as LUNESTA under NDA 021476 on 15 December 2004, with generic applications from 2011.

Participants / model
Not a clinical population
Treatment
Drug applications
Follow-up
Search run on 9 October 2026
Study design
Dated US approval-record search
Funding
not stated in the source

This supports a dated, US-scoped statement only: no FDA-approved zopiclone product was located.

Read the original source
PubChem: zopiclone racemate and eszopiclone enantiomer identity

Chemical identity record

National Library of Medicine. PubChem compound records CID 5735 (zopiclone) and CID 969472 (eszopiclone).

Zopiclone is a racemate: PubChem CID 5735, C17H17ClN6O3, 388.8 g/mol, CAS 43200-80-2. Eszopiclone, the (S)-enantiomer sold in the US, is CID 969472 with the same formula and weight, CAS 138729-47-2.

Participants / model
Chemical identity, not a clinical population
Treatment
Racemate and single enantiomer
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Data for one should not be carried over to the other without saying so. Supplier material sold as zopiclone has not been compared with either record.

Read the original source

What did the insomnia trials find?

A network meta-analysis of 154 double-blind randomized trials found zopiclone more efficacious than placebo for acute insomnia and more efficacious than melatonin, ramelteon and zaleplon. It also caused more dropouts due to adverse events than placebo and eszopiclone.

A systematic review and network meta-analysis of 154 double-blind randomized trials (30 interventions, 44,089 participants) in adults with insomnia disorder found zopiclone among the drugs more efficacious than placebo for acute treatment (group SMD range 0.36 to 0.83, high to moderate certainty). It was also more efficacious than melatonin, ramelteon, and zaleplon.

Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty). In long-term analyses, eszopiclone and lemborexant were the drugs reported as more effective than placebo.

Network meta-analysis: 154 trials, 44,089 participants, zopiclone dropouts OR 2.00

Systematic review and meta-analysis

De Crescenzo F et al. Lancet. 2022;400(10347):170-184. PMID 35843245.

Across 154 double-blind randomized trials (30 interventions, 44,089 participants), zopiclone was among the drugs more efficacious than placebo for acute treatment of insomnia disorder (group SMD range 0.36 to 0.83, high to moderate certainty), and more efficacious than melatonin, ramelteon, and zaleplon. Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty). In long-term analyses, eszopiclone and lemborexant were the drugs reported as more effective than placebo.

Participants / model
Adults with insomnia disorder in randomized trials
Treatment
Oral hypnotics, including zopiclone
Follow-up
Acute treatment and long-term analyses
Study design
Systematic review and network meta-analysis of 154 double-blind randomized trials
Funding
not stated in the source

Efficacy is for acute treatment. The long-term analyses did not name zopiclone as more effective than placebo.

Read the original source

Does zopiclone impair driving the next morning?

Yes in the experiments found. On-road studies show consistent next-morning impairment larger than at a 0.05% blood alcohol level, and a simulator study in adults with insomnia found more collisions with zopiclone than placebo.

A review of eight standardized on-the-road driving studies found that zopiclone 7.5 mg at bedtime consistently impaired driving the next morning. Across 191 healthy volunteers, the standard deviation of lateral position rose by an average of 3.0 cm over placebo (combined effect size 0.782, 95% CI 0.620 to 0.944), more than the 2.4 cm rise reported at a blood alcohol concentration of 0.05%. Adult and elderly volunteers did not differ. Zopiclone 7.5 mg is used as the positive control in these studies.

In 23 adults with primary insomnia given single and 7-night bedtime doses in a crossover design, driving-simulator tests 9 to 11 hours later showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

No on-road head-to-head comparison of zopiclone with a benzodiazepine was located.

On-road review: 8 studies, 191 volunteers, SDLP up 3.0 cm

Systematic review and meta-analysis

Verster JC et al. Curr Drug Saf. 2011;6(4):209-18. PMID 22129315.

Zopiclone 7.5 mg at bedtime consistently impaired driving the next morning. Across 191 healthy volunteers, the standard deviation of lateral position rose by an average of 3.0 cm over placebo (combined effect size 0.782, 95% CI 0.620 to 0.944), more than the 2.4 cm rise reported at a blood alcohol concentration of 0.05%. Adult and elderly volunteers did not differ. Zopiclone 7.5 mg is used as the positive control in these studies.

Participants / model
191 healthy adult and elderly volunteers
Treatment
Oral zopiclone 7.5 mg at bedtime
Follow-up
Next-morning driving tests
Study design
Review with meta-analysis of eight experimental on-road studies
Funding
not stated in the source

Healthy volunteers, not people with insomnia. No on-road head-to-head comparison of zopiclone with a benzodiazepine was located.

Read the original source
Simulator crossover: 23 adults with insomnia, zopiclone more collisions

Randomized controlled trial

Staner L et al. Psychopharmacology (Berl). 2005;181(4):790-8. PMID 16025317.

Driving-simulator tests 9 to 11 hours after dosing showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

Participants / model
23 adults with DSM-IV primary insomnia (9 men, 14 women)
Treatment
Oral zopiclone 7.5 mg, lormetazepam 1 mg, zolpidem 10 mg, or placebo at bedtime
Follow-up
Single and 7-night bedtime doses; driving tests 9 to 11 hours later
Study design
Crossover trial
Funding
not stated in the source

A small trial in people with insomnia. It found next-day impairment with both zopiclone and lormetazepam.

Read the original source

What do crash studies show for zopiclone?

The results are mixed. Norway found a higher accident rate in the week after hypnotic fills for zopiclone and zolpidem combined, France found no association for zopiclone, and Tayside found higher accident risk on days of use.

Following all Norwegians aged 18 to 69 (3.1 million) from January 2004 to September 2006, the week after filling a hypnotic prescription carried a higher road-traffic accident rate than unexposed time: standardized incidence ratio 2.3 (95% CI 2.0 to 2.7) for zopiclone and zolpidem combined, 2.7 (1.8 to 3.9) for nitrazepam, and 4.0 (2.4 to 6.4) for flunitrazepam. Zopiclone accounted for 129 of the exposed accidents. Prescription fills stand in for use.

In 72,685 drivers involved in injury crashes in France from 2005 to 2008, users of benzodiazepine hypnotics had higher odds of being responsible for the crash (OR 1.39, 95% CI 1.08 to 1.79), as did 155 drivers dispensed more than one zolpidem pill a day (OR 2.46, 95% CI 1.70 to 3.56). No association was found for zopiclone.

A case-crossover study of 19,386 drivers in Tayside, UK, with a first road-traffic accident between 1992 and 1995 (1,731 of them users of psychoactive drugs) found higher accident risk on days of benzodiazepine use (OR 1.62, 95% CI 1.24 to 2.12; 235 drivers). The increase was significant for long-half-life anxiolytics and for short-half-life hypnotics, which were all zopiclone, and the authors advised zopiclone users not to drive.

Norway registry: 3.1 million residents, zopiclone and zolpidem SIR 2.3

Human study

Gustavsen I et al. Sleep Med. 2008;9(8):818-22. PMID 18226959.

The week after filling a hypnotic prescription carried a higher road-traffic accident rate than unexposed time: standardized incidence ratio 2.3 (95% CI 2.0 to 2.7) for zopiclone and zolpidem combined, 2.7 (1.8 to 3.9) for nitrazepam, and 4.0 (2.4 to 6.4) for flunitrazepam. Zopiclone accounted for 129 of the exposed accidents.

Participants / model
3.1 million Norwegian residents aged 18 to 69
Treatment
Dispensed oral hypnotics
Follow-up
January 2004 to September 2006
Study design
Population registry cohort
Funding
not stated in the source

Prescription fills stand in for use. Zopiclone and zolpidem are reported together.

Read the original source
France crashes: 72,685 drivers, no association for zopiclone

Human study

Orriols L et al. Clin Pharmacol Ther. 2011;89(4):595-601. PMID 21368756.

Users of benzodiazepine hypnotics had higher odds of being responsible for the crash (OR 1.39, 95% CI 1.08 to 1.79), as did 155 drivers dispensed more than one zolpidem pill a day (OR 2.46, 95% CI 1.70 to 3.56). No association was found for zopiclone.

Participants / model
72,685 French drivers in injury-related crashes
Treatment
Dispensed oral hypnotics
Follow-up
Crashes from 2005 to 2008
Study design
Observational study using linked national databases
Funding
not stated in the source

Dispensing stands in for use.

Read the original source
Tayside: 19,386 drivers, higher accident risk on benzodiazepine days

Human study

Barbone F et al. Lancet. 1998;352(9137):1331-6. PMID 9802269.

Accident risk was higher on days of benzodiazepine use (OR 1.62, 95% CI 1.24 to 2.12; 235 drivers). The increase was significant for long-half-life anxiolytics and for short-half-life hypnotics, which were all zopiclone, and the authors advised zopiclone users not to drive.

Participants / model
19,386 drivers aged 18 and over in Tayside, UK (1,731 of them users of psychoactive drugs)
Treatment
Dispensed oral psychoactive drugs
Follow-up
First road-traffic accident between 1992 and 1995
Study design
Observational case-crossover study
Funding
not stated in the source

Observational; dispensing stands in for use.

Read the original source

Is zopiclone cleaner the next day than benzodiazepines, and does it help sleep disrupted by stimulants or training?

Short-term insomnia is supported. A general cleaner next-day profile than benzodiazepines is not, the stimulant claim has no trial found behind it, and the training claim rests on two small athlete studies.

Sellers market zopiclone for short-term insomnia, including sleep disrupted by stimulants or hard training, with a cleaner next-day profile than benzodiazepines. Short-term insomnia is the labeled use and is supported by the network meta-analysis above.

A cleaner next-day profile than benzodiazepines in general is not supported. On-road studies show next-morning impairment larger than at a 0.05% blood alcohol level, a simulator study in adults with insomnia found next-day impairment with both zopiclone and lormetazepam, and crash studies are mixed. The one favorable head-to-head result is against loprazolam in 12 athletes.

A PubMed search on 9 October 2026 for zopiclone with amphetamine, amphetamines, methamphetamine, cocaine, stimulant, stimulants, modafinil, or caffeine in the title or abstract returned 61 records. None tested zopiclone for sleep disrupted by stimulants. They covered forensic toxicology and drug-screening methods, roadside, impaired-driver, and sexual-assault toxicology surveys, misuse and poisoning reports, clinical reviews (including shift-work sleep), animal and in vitro studies, and a 1992 study in which caffeine partly offset zopiclone's psychomotor effects in healthy subjects.

PubMed search, 9 October 2026: 61 records, none on sleep disrupted by stimulants

PubMed search record

PubMed search run on 9 October 2026: zopiclone[tiab] AND (amphetamine OR amphetamines OR methamphetamine OR cocaine OR stimulant OR stimulants OR modafinil OR caffeine)[tiab]. 61 records returned.

The search returned 61 records. None tested zopiclone for sleep disrupted by stimulants. They covered forensic toxicology and drug-screening methods, roadside, impaired-driver, and sexual-assault toxicology surveys, misuse and poisoning reports, clinical reviews (including shift-work sleep), animal and in vitro studies, and a 1992 study in which caffeine partly offset zopiclone's psychomotor effects in healthy subjects.

Participants / model
Records returned, not a population
Treatment
Not applicable
Follow-up
Search run on 9 October 2026
Study design
Literature search
Funding
not stated in the source

A search result shows what PubMed returned on that date. It is not proof that no unindexed study exists.

Read the original source
On-road review: 8 studies, 191 volunteers, SDLP up 3.0 cm

Systematic review and meta-analysis

Verster JC et al. Curr Drug Saf. 2011;6(4):209-18. PMID 22129315.

Zopiclone 7.5 mg at bedtime consistently impaired driving the next morning. Across 191 healthy volunteers, the standard deviation of lateral position rose by an average of 3.0 cm over placebo (combined effect size 0.782, 95% CI 0.620 to 0.944), more than the 2.4 cm rise reported at a blood alcohol concentration of 0.05%. Adult and elderly volunteers did not differ. Zopiclone 7.5 mg is used as the positive control in these studies.

Participants / model
191 healthy adult and elderly volunteers
Treatment
Oral zopiclone 7.5 mg at bedtime
Follow-up
Next-morning driving tests
Study design
Review with meta-analysis of eight experimental on-road studies
Funding
not stated in the source

Healthy volunteers, not people with insomnia. No on-road head-to-head comparison of zopiclone with a benzodiazepine was located.

Read the original source
Simulator crossover: 23 adults with insomnia, zopiclone more collisions

Randomized controlled trial

Staner L et al. Psychopharmacology (Berl). 2005;181(4):790-8. PMID 16025317.

Driving-simulator tests 9 to 11 hours after dosing showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

Participants / model
23 adults with DSM-IV primary insomnia (9 men, 14 women)
Treatment
Oral zopiclone 7.5 mg, lormetazepam 1 mg, zolpidem 10 mg, or placebo at bedtime
Follow-up
Single and 7-night bedtime doses; driving tests 9 to 11 hours later
Study design
Crossover trial
Funding
not stated in the source

A small trial in people with insomnia. It found next-day impairment with both zopiclone and lormetazepam.

Read the original source
12 athletes: no performance change 10 hours after zopiclone; loprazolam more hangover

Randomized controlled trial

Grobler LA et al. Clin J Sport Med. 2000;10(2):123-8. PMID 10798794.

Tests 10 hours after zopiclone 7.5 mg showed no significant change in eye-hand coordination, 30-m sprint, agility, VO2max, or treadmill time to exhaustion. The benzodiazepine loprazolam 2 mg produced more reported hangover (8 of 11 versus 3 of 11 on zopiclone) and more missed responses on eye-hand coordination. A PubMed search on 9 October 2026 for zopiclone with athlete, athletes, sport, sports, exercise, or training in title or abstract returned 20 records; this trial and the 8-athlete study were the only trials in athletes.

Participants / model
12 athletes (hangover ratings reported for 11)
Treatment
Single oral dose of zopiclone 7.5 mg, loprazolam 2 mg, or placebo
Follow-up
Psychomotor and physical performance tests 10 hours after dosing
Study design
Double-blind placebo-controlled crossover trial
Funding
not stated in the source

This favors zopiclone over one benzodiazepine in a small group of athletes. It did not study sleep disrupted by training.

Read the original source

What did the two athlete studies show?

In 12 athletes, performance tests 10 hours after zopiclone showed no significant change, and loprazolam produced more reported hangover. In 8 athletes, zopiclone improved self-rated sleep without a significant change in performance tests.

In a double-blind placebo-controlled crossover trial in 12 athletes, tests 10 hours after zopiclone 7.5 mg showed no significant change in eye-hand coordination, 30-m sprint, agility, VO2max, or treadmill time to exhaustion. The benzodiazepine loprazolam 2 mg produced more reported hangover (8 of 11 versus 3 of 11 on zopiclone) and more missed responses on eye-hand coordination. This favors zopiclone over one benzodiazepine in a small group of athletes.

In a double-blind crossover study in 8 athletes given zopiclone 7.5 mg or placebo in two sessions of 2 nights each, zopiclone improved self-rated sleep quality and daytime sleepiness and did not significantly change psychomotor or physical performance tests.

Neither study enrolled people whose sleep was disrupted by training. A PubMed search on 9 October 2026 for zopiclone with athlete, athletes, sport, sports, exercise, or training in the title or abstract returned 20 records, and these two were the only trials in athletes.

12 athletes: no performance change 10 hours after zopiclone; loprazolam more hangover

Randomized controlled trial

Grobler LA et al. Clin J Sport Med. 2000;10(2):123-8. PMID 10798794.

Tests 10 hours after zopiclone 7.5 mg showed no significant change in eye-hand coordination, 30-m sprint, agility, VO2max, or treadmill time to exhaustion. The benzodiazepine loprazolam 2 mg produced more reported hangover (8 of 11 versus 3 of 11 on zopiclone) and more missed responses on eye-hand coordination. A PubMed search on 9 October 2026 for zopiclone with athlete, athletes, sport, sports, exercise, or training in title or abstract returned 20 records; this trial and the 8-athlete study were the only trials in athletes.

Participants / model
12 athletes (hangover ratings reported for 11)
Treatment
Single oral dose of zopiclone 7.5 mg, loprazolam 2 mg, or placebo
Follow-up
Psychomotor and physical performance tests 10 hours after dosing
Study design
Double-blind placebo-controlled crossover trial
Funding
not stated in the source

This favors zopiclone over one benzodiazepine in a small group of athletes. It did not study sleep disrupted by training.

Read the original source
8 athletes: better self-rated sleep, no change in performance tests

Randomized controlled trial

Tafti M et al. Prog Neuropsychopharmacol Biol Psychiatry. 1992;16(1):55-63. PMID 1557507.

Zopiclone improved self-rated sleep quality and daytime sleepiness and did not significantly change psychomotor or physical performance tests.

Participants / model
8 athletes
Treatment
Oral zopiclone 7.5 mg at night for 2 nights per session, or placebo
Follow-up
Two sessions of 2 nights each
Study design
Double-blind crossover study
Funding
not stated in the source

A small study. It did not enroll people whose sleep was disrupted by training.

Read the original source

How does zopiclone work, and what does the body do with it?

The sources reviewed do not describe zopiclone's receptor mechanism. The UK label gives an elimination half-life of about 5 hours, with metabolism mainly by CYP3A4.

The sources reviewed do not describe zopiclone's receptor mechanism, so none is stated here. Zopiclone is a racemate, and eszopiclone is its S-enantiomer. In the driving study in adults with insomnia, zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

The UK label gives peak levels within 1.5 to 2 hours and an elimination half-life of about 5 hours. Metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

UK Zimovane SmPC, text revised 11 February 2026: indication, warnings, PK

Official label

electronic Medicines Compendium (medicines.org.uk). Zimovane film-coated tablets, summary of product characteristics, text revised 11 February 2026. Product 2855.

The summary of product characteristics indicates zopiclone for short-term treatment of insomnia in adults and limits treatment to the short term. It is contraindicated in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common. Peak levels come within 1.5 to 2 hours, the elimination half-life is about 5 hours, metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

Participants / model
Adults with insomnia; label PK participants
Treatment
Zimovane film-coated oral tablets
Follow-up
Text revised 11 February 2026
Study design
Official UK summary of product characteristics
Funding
not stated in the source

A UK label, not an FDA label. Dosing details are left out of this page.

Read the original source
Simulator crossover: 23 adults with insomnia, zopiclone more collisions

Randomized controlled trial

Staner L et al. Psychopharmacology (Berl). 2005;181(4):790-8. PMID 16025317.

Driving-simulator tests 9 to 11 hours after dosing showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

Participants / model
23 adults with DSM-IV primary insomnia (9 men, 14 women)
Treatment
Oral zopiclone 7.5 mg, lormetazepam 1 mg, zolpidem 10 mg, or placebo at bedtime
Follow-up
Single and 7-night bedtime doses; driving tests 9 to 11 hours later
Study design
Crossover trial
Funding
not stated in the source

A small trial in people with insomnia. It found next-day impairment with both zopiclone and lormetazepam.

Read the original source
PubChem: zopiclone racemate and eszopiclone enantiomer identity

Chemical identity record

National Library of Medicine. PubChem compound records CID 5735 (zopiclone) and CID 969472 (eszopiclone).

Zopiclone is a racemate: PubChem CID 5735, C17H17ClN6O3, 388.8 g/mol, CAS 43200-80-2. Eszopiclone, the (S)-enantiomer sold in the US, is CID 969472 with the same formula and weight, CAS 138729-47-2.

Participants / model
Chemical identity, not a clinical population
Treatment
Racemate and single enantiomer
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Data for one should not be carried over to the other without saying so. Supplier material sold as zopiclone has not been compared with either record.

Read the original source

What risks do the labels and studies report?

The UK label warns about dependence, abuse and withdrawal, psychomotor impairment including impaired driving, and complex sleep behaviors such as sleep-driving, and it lists contraindications including respiratory failure and severe sleep apnea.

The UK label contraindicates zopiclone in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common.

Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty) in the network meta-analysis.

The next two points are about eszopiclone, not zopiclone, and are not carried over to zopiclone. The LUNESTA label carries a boxed warning for complex sleep behaviors, including sleep-driving, some causing serious injury or death. In a double-blind study of 91 healthy adults aged 25 to 40, eszopiclone 3 mg caused next-morning psychomotor and memory impairment that was most severe at 7.5 hours and still present and potentially clinically meaningful at 11.5 hours, and subjects did not consistently perceive it.

UK Zimovane SmPC, text revised 11 February 2026: indication, warnings, PK

Official label

electronic Medicines Compendium (medicines.org.uk). Zimovane film-coated tablets, summary of product characteristics, text revised 11 February 2026. Product 2855.

The summary of product characteristics indicates zopiclone for short-term treatment of insomnia in adults and limits treatment to the short term. It is contraindicated in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common. Peak levels come within 1.5 to 2 hours, the elimination half-life is about 5 hours, metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

Participants / model
Adults with insomnia; label PK participants
Treatment
Zimovane film-coated oral tablets
Follow-up
Text revised 11 February 2026
Study design
Official UK summary of product characteristics
Funding
not stated in the source

A UK label, not an FDA label. Dosing details are left out of this page.

Read the original source
Network meta-analysis: 154 trials, 44,089 participants, zopiclone dropouts OR 2.00

Systematic review and meta-analysis

De Crescenzo F et al. Lancet. 2022;400(10347):170-184. PMID 35843245.

Across 154 double-blind randomized trials (30 interventions, 44,089 participants), zopiclone was among the drugs more efficacious than placebo for acute treatment of insomnia disorder (group SMD range 0.36 to 0.83, high to moderate certainty), and more efficacious than melatonin, ramelteon, and zaleplon. Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty). In long-term analyses, eszopiclone and lemborexant were the drugs reported as more effective than placebo.

Participants / model
Adults with insomnia disorder in randomized trials
Treatment
Oral hypnotics, including zopiclone
Follow-up
Acute treatment and long-term analyses
Study design
Systematic review and network meta-analysis of 154 double-blind randomized trials
Funding
not stated in the source

Efficacy is for acute treatment. The long-term analyses did not name zopiclone as more effective than placebo.

Read the original source
LUNESTA label, eszopiclone, version effective 8 January 2025: boxed warning, next-morning impairment

FDA prescribing information

DailyMed, U.S. National Library of Medicine. LUNESTA (eszopiclone) oral tablets, prescribing information, label version effective 8 January 2025. Set ID 3821f4b7-a3c8-4920-ba80-18aa96532c09.

This is eszopiclone, not zopiclone. LUNESTA carries a boxed warning for complex sleep behaviors, including sleep-driving, some causing serious injury or death. The label ties higher doses to higher morning blood levels and a higher risk of next-day impairment of driving. In a double-blind study of 91 healthy adults aged 25 to 40, eszopiclone 3 mg caused next-morning psychomotor and memory impairment that was most severe at 7.5 hours and still present and potentially clinically meaningful at 11.5 hours, and subjects did not consistently perceive it.

Participants / model
Adults with insomnia; 91 healthy adults aged 25 to 40 in the residual-effects study
Treatment
LUNESTA (eszopiclone) oral tablets
Follow-up
Label version effective 8 January 2025
Study design
FDA prescribing information
Funding
not stated in the source

Eszopiclone is the S-enantiomer of zopiclone. Its label data are not zopiclone data and are not carried over to zopiclone. Dosing details are left out of this page.

Read the original source

Why does zopiclone sit in A tier?

Long use in the EU, current UK authorization, Canadian marketing and network meta-analysis support for short-term efficacy support the A. Next-morning driving impairment, dropouts due to adverse events and the lack of a located US approval hold it back.

Zopiclone has been used for short-term insomnia in the EU since the mid-1980s, remains authorized in the UK and is marketed in Canada, and network meta-analysis supports short-term efficacy over placebo. The record has limits: 7.5 mg at bedtime consistently impaired next-morning driving in on-road studies, zopiclone caused more dropouts due to adverse events than placebo and eszopiclone, the UK label limits treatment to the short term and carries dependence and complex-sleep-behavior warnings, and no US approval was located.

The supplier claim gets its own verdict. Short-term insomnia is supported. A cleaner next-day profile than benzodiazepines in general is not, because on-road studies show impairment larger than at a 0.05% blood alcohol level, a simulator study found next-day impairment with both zopiclone and lormetazepam, and crash studies are mixed. The one favorable head-to-head result is against loprazolam in 12 athletes. The stimulant part has no trial, and the training part rests on two small next-day performance studies in athletes, neither in people whose sleep was disrupted by training.

EMA: zopiclone in the EU since the mid-1980s; Lunivia withdrawn 13 May 2009

Regulatory record

European Medicines Agency. Lunivia (eszopiclone), withdrawn application record. EMA lists no centrally authorized zopiclone product.

EMA states that zopiclone has been available in the EU as a treatment for insomnia since the mid-1980s and describes eszopiclone as a purified form of one of zopiclone's two enantiomers. CHMP gave Lunivia (eszopiclone) a positive opinion for insomnia but concluded that eszopiclone could not be considered a new active substance; the company withdrew the application on 13 May 2009. EMA's centrally authorized medicines data list no zopiclone product (read 9 October 2026), so EU zopiclone products are not centrally authorized.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Regulatory history from the mid-1980s to 2009
Study design
Official EMA record
Funding
not stated in the source

The record is about eszopiclone's withdrawn application and describes zopiclone's EU history. EU zopiclone products are authorized nationally, not centrally.

Read the original source
UK Zimovane SmPC, text revised 11 February 2026: indication, warnings, PK

Official label

electronic Medicines Compendium (medicines.org.uk). Zimovane film-coated tablets, summary of product characteristics, text revised 11 February 2026. Product 2855.

The summary of product characteristics indicates zopiclone for short-term treatment of insomnia in adults and limits treatment to the short term. It is contraindicated in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common. Peak levels come within 1.5 to 2 hours, the elimination half-life is about 5 hours, metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

Participants / model
Adults with insomnia; label PK participants
Treatment
Zimovane film-coated oral tablets
Follow-up
Text revised 11 February 2026
Study design
Official UK summary of product characteristics
Funding
not stated in the source

A UK label, not an FDA label. Dosing details are left out of this page.

Read the original source
Health Canada: IMOVANE 7.5 mg marketed; 5 mg cancelled post-market 24 May 2022

Regulatory record

Health Canada. Drug Product Database status record for IMOVANE oral tablets (DIN 01926799, DIN 02216167), read through the database API.

Health Canada's Drug Product Database lists IMOVANE 7.5 mg oral tablets (DIN 01926799, Sanofi-Aventis Canada) as marketed. A 5 mg IMOVANE tablet (DIN 02216167) is listed as cancelled post-market on 24 May 2022.

Participants / model
Not a clinical population
Treatment
Oral zopiclone tablets
Follow-up
Status as read on 9 October 2026
Study design
Official regulator database record
Funding
not stated in the source

The Canadian status comes from the Drug Product Database API record, not a product monograph.

Read the original source
Network meta-analysis: 154 trials, 44,089 participants, zopiclone dropouts OR 2.00

Systematic review and meta-analysis

De Crescenzo F et al. Lancet. 2022;400(10347):170-184. PMID 35843245.

Across 154 double-blind randomized trials (30 interventions, 44,089 participants), zopiclone was among the drugs more efficacious than placebo for acute treatment of insomnia disorder (group SMD range 0.36 to 0.83, high to moderate certainty), and more efficacious than melatonin, ramelteon, and zaleplon. Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty). In long-term analyses, eszopiclone and lemborexant were the drugs reported as more effective than placebo.

Participants / model
Adults with insomnia disorder in randomized trials
Treatment
Oral hypnotics, including zopiclone
Follow-up
Acute treatment and long-term analyses
Study design
Systematic review and network meta-analysis of 154 double-blind randomized trials
Funding
not stated in the source

Efficacy is for acute treatment. The long-term analyses did not name zopiclone as more effective than placebo.

Read the original source
On-road review: 8 studies, 191 volunteers, SDLP up 3.0 cm

Systematic review and meta-analysis

Verster JC et al. Curr Drug Saf. 2011;6(4):209-18. PMID 22129315.

Zopiclone 7.5 mg at bedtime consistently impaired driving the next morning. Across 191 healthy volunteers, the standard deviation of lateral position rose by an average of 3.0 cm over placebo (combined effect size 0.782, 95% CI 0.620 to 0.944), more than the 2.4 cm rise reported at a blood alcohol concentration of 0.05%. Adult and elderly volunteers did not differ. Zopiclone 7.5 mg is used as the positive control in these studies.

Participants / model
191 healthy adult and elderly volunteers
Treatment
Oral zopiclone 7.5 mg at bedtime
Follow-up
Next-morning driving tests
Study design
Review with meta-analysis of eight experimental on-road studies
Funding
not stated in the source

Healthy volunteers, not people with insomnia. No on-road head-to-head comparison of zopiclone with a benzodiazepine was located.

Read the original source
Simulator crossover: 23 adults with insomnia, zopiclone more collisions

Randomized controlled trial

Staner L et al. Psychopharmacology (Berl). 2005;181(4):790-8. PMID 16025317.

Driving-simulator tests 9 to 11 hours after dosing showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

Participants / model
23 adults with DSM-IV primary insomnia (9 men, 14 women)
Treatment
Oral zopiclone 7.5 mg, lormetazepam 1 mg, zolpidem 10 mg, or placebo at bedtime
Follow-up
Single and 7-night bedtime doses; driving tests 9 to 11 hours later
Study design
Crossover trial
Funding
not stated in the source

A small trial in people with insomnia. It found next-day impairment with both zopiclone and lormetazepam.

Read the original source
openFDA, 9 October 2026: no zopiclone application; eszopiclone approved 2004

Regulatory record

U.S. Food and Drug Administration. openFDA Drugs@FDA queries for zopiclone by brand or generic name and by active ingredient, run on 9 October 2026, with a DailyMed label search.

openFDA Drugs@FDA queries for zopiclone, by brand or generic name and by active ingredient, returned no application on 9 October 2026, and a DailyMed search returned no zopiclone label. The S-enantiomer eszopiclone was approved as LUNESTA under NDA 021476 on 15 December 2004, with generic applications from 2011.

Participants / model
Not a clinical population
Treatment
Drug applications
Follow-up
Search run on 9 October 2026
Study design
Dated US approval-record search
Funding
not stated in the source

This supports a dated, US-scoped statement only: no FDA-approved zopiclone product was located.

Read the original source

Studies and sources

EMA: zopiclone in the EU since the mid-1980s; Lunivia withdrawn 13 May 2009

Regulatory record

European Medicines Agency. Lunivia (eszopiclone), withdrawn application record. EMA lists no centrally authorized zopiclone product.

EMA states that zopiclone has been available in the EU as a treatment for insomnia since the mid-1980s and describes eszopiclone as a purified form of one of zopiclone's two enantiomers. CHMP gave Lunivia (eszopiclone) a positive opinion for insomnia but concluded that eszopiclone could not be considered a new active substance; the company withdrew the application on 13 May 2009. EMA's centrally authorized medicines data list no zopiclone product (read 9 October 2026), so EU zopiclone products are not centrally authorized.

Participants / model
Not a clinical population
Treatment
Oral tablets
Follow-up
Regulatory history from the mid-1980s to 2009
Study design
Official EMA record
Funding
not stated in the source

The record is about eszopiclone's withdrawn application and describes zopiclone's EU history. EU zopiclone products are authorized nationally, not centrally.

Read the original source
UK Zimovane SmPC, text revised 11 February 2026: indication, warnings, PK

Official label

electronic Medicines Compendium (medicines.org.uk). Zimovane film-coated tablets, summary of product characteristics, text revised 11 February 2026. Product 2855.

The summary of product characteristics indicates zopiclone for short-term treatment of insomnia in adults and limits treatment to the short term. It is contraindicated in myasthenia gravis, respiratory failure, severe sleep apnea, severe hepatic insufficiency, and after a previous complex sleep behavior. Warnings cover dependence, abuse, and withdrawal; psychomotor impairment, including impaired driving, with the risk increased when zopiclone is taken close in time to tasks needing alertness, above the recommended dose, or with alcohol or other CNS depressants; and complex sleep behaviors such as sleep-driving. Bitter taste and residual somnolence are listed as common. Peak levels come within 1.5 to 2 hours, the elimination half-life is about 5 hours, metabolism is mainly by CYP3A4 with a CYP2C8 contribution, and food does not change absorption.

Participants / model
Adults with insomnia; label PK participants
Treatment
Zimovane film-coated oral tablets
Follow-up
Text revised 11 February 2026
Study design
Official UK summary of product characteristics
Funding
not stated in the source

A UK label, not an FDA label. Dosing details are left out of this page.

Read the original source
Health Canada: IMOVANE 7.5 mg marketed; 5 mg cancelled post-market 24 May 2022

Regulatory record

Health Canada. Drug Product Database status record for IMOVANE oral tablets (DIN 01926799, DIN 02216167), read through the database API.

Health Canada's Drug Product Database lists IMOVANE 7.5 mg oral tablets (DIN 01926799, Sanofi-Aventis Canada) as marketed. A 5 mg IMOVANE tablet (DIN 02216167) is listed as cancelled post-market on 24 May 2022.

Participants / model
Not a clinical population
Treatment
Oral zopiclone tablets
Follow-up
Status as read on 9 October 2026
Study design
Official regulator database record
Funding
not stated in the source

The Canadian status comes from the Drug Product Database API record, not a product monograph.

Read the original source
LUNESTA label, eszopiclone, version effective 8 January 2025: boxed warning, next-morning impairment

FDA prescribing information

DailyMed, U.S. National Library of Medicine. LUNESTA (eszopiclone) oral tablets, prescribing information, label version effective 8 January 2025. Set ID 3821f4b7-a3c8-4920-ba80-18aa96532c09.

This is eszopiclone, not zopiclone. LUNESTA carries a boxed warning for complex sleep behaviors, including sleep-driving, some causing serious injury or death. The label ties higher doses to higher morning blood levels and a higher risk of next-day impairment of driving. In a double-blind study of 91 healthy adults aged 25 to 40, eszopiclone 3 mg caused next-morning psychomotor and memory impairment that was most severe at 7.5 hours and still present and potentially clinically meaningful at 11.5 hours, and subjects did not consistently perceive it.

Participants / model
Adults with insomnia; 91 healthy adults aged 25 to 40 in the residual-effects study
Treatment
LUNESTA (eszopiclone) oral tablets
Follow-up
Label version effective 8 January 2025
Study design
FDA prescribing information
Funding
not stated in the source

Eszopiclone is the S-enantiomer of zopiclone. Its label data are not zopiclone data and are not carried over to zopiclone. Dosing details are left out of this page.

Read the original source
PubChem: zopiclone racemate and eszopiclone enantiomer identity

Chemical identity record

National Library of Medicine. PubChem compound records CID 5735 (zopiclone) and CID 969472 (eszopiclone).

Zopiclone is a racemate: PubChem CID 5735, C17H17ClN6O3, 388.8 g/mol, CAS 43200-80-2. Eszopiclone, the (S)-enantiomer sold in the US, is CID 969472 with the same formula and weight, CAS 138729-47-2.

Participants / model
Chemical identity, not a clinical population
Treatment
Racemate and single enantiomer
Follow-up
Not applicable
Study design
NLM chemical record
Funding
not stated in the source

Data for one should not be carried over to the other without saying so. Supplier material sold as zopiclone has not been compared with either record.

Read the original source
Network meta-analysis: 154 trials, 44,089 participants, zopiclone dropouts OR 2.00

Systematic review and meta-analysis

De Crescenzo F et al. Lancet. 2022;400(10347):170-184. PMID 35843245.

Across 154 double-blind randomized trials (30 interventions, 44,089 participants), zopiclone was among the drugs more efficacious than placebo for acute treatment of insomnia disorder (group SMD range 0.36 to 0.83, high to moderate certainty), and more efficacious than melatonin, ramelteon, and zaleplon. Zopiclone caused more dropouts due to adverse events than placebo (OR 2.00, 95% CI 1.28 to 3.13, very low certainty) and than eszopiclone (OR 1.82, 95% CI 1.01 to 3.33, low certainty). In long-term analyses, eszopiclone and lemborexant were the drugs reported as more effective than placebo.

Participants / model
Adults with insomnia disorder in randomized trials
Treatment
Oral hypnotics, including zopiclone
Follow-up
Acute treatment and long-term analyses
Study design
Systematic review and network meta-analysis of 154 double-blind randomized trials
Funding
not stated in the source

Efficacy is for acute treatment. The long-term analyses did not name zopiclone as more effective than placebo.

Read the original source
On-road review: 8 studies, 191 volunteers, SDLP up 3.0 cm

Systematic review and meta-analysis

Verster JC et al. Curr Drug Saf. 2011;6(4):209-18. PMID 22129315.

Zopiclone 7.5 mg at bedtime consistently impaired driving the next morning. Across 191 healthy volunteers, the standard deviation of lateral position rose by an average of 3.0 cm over placebo (combined effect size 0.782, 95% CI 0.620 to 0.944), more than the 2.4 cm rise reported at a blood alcohol concentration of 0.05%. Adult and elderly volunteers did not differ. Zopiclone 7.5 mg is used as the positive control in these studies.

Participants / model
191 healthy adult and elderly volunteers
Treatment
Oral zopiclone 7.5 mg at bedtime
Follow-up
Next-morning driving tests
Study design
Review with meta-analysis of eight experimental on-road studies
Funding
not stated in the source

Healthy volunteers, not people with insomnia. No on-road head-to-head comparison of zopiclone with a benzodiazepine was located.

Read the original source
Simulator crossover: 23 adults with insomnia, zopiclone more collisions

Randomized controlled trial

Staner L et al. Psychopharmacology (Berl). 2005;181(4):790-8. PMID 16025317.

Driving-simulator tests 9 to 11 hours after dosing showed more collisions with zopiclone 7.5 mg than with placebo, more speed deviation with the benzodiazepine lormetazepam 1 mg, and no difference from placebo with zolpidem 10 mg. Zopiclone and lormetazepam both produced benzodiazepine-like EEG changes before and during driving.

Participants / model
23 adults with DSM-IV primary insomnia (9 men, 14 women)
Treatment
Oral zopiclone 7.5 mg, lormetazepam 1 mg, zolpidem 10 mg, or placebo at bedtime
Follow-up
Single and 7-night bedtime doses; driving tests 9 to 11 hours later
Study design
Crossover trial
Funding
not stated in the source

A small trial in people with insomnia. It found next-day impairment with both zopiclone and lormetazepam.

Read the original source
Norway registry: 3.1 million residents, zopiclone and zolpidem SIR 2.3

Human study

Gustavsen I et al. Sleep Med. 2008;9(8):818-22. PMID 18226959.

The week after filling a hypnotic prescription carried a higher road-traffic accident rate than unexposed time: standardized incidence ratio 2.3 (95% CI 2.0 to 2.7) for zopiclone and zolpidem combined, 2.7 (1.8 to 3.9) for nitrazepam, and 4.0 (2.4 to 6.4) for flunitrazepam. Zopiclone accounted for 129 of the exposed accidents.

Participants / model
3.1 million Norwegian residents aged 18 to 69
Treatment
Dispensed oral hypnotics
Follow-up
January 2004 to September 2006
Study design
Population registry cohort
Funding
not stated in the source

Prescription fills stand in for use. Zopiclone and zolpidem are reported together.

Read the original source
France crashes: 72,685 drivers, no association for zopiclone

Human study

Orriols L et al. Clin Pharmacol Ther. 2011;89(4):595-601. PMID 21368756.

Users of benzodiazepine hypnotics had higher odds of being responsible for the crash (OR 1.39, 95% CI 1.08 to 1.79), as did 155 drivers dispensed more than one zolpidem pill a day (OR 2.46, 95% CI 1.70 to 3.56). No association was found for zopiclone.

Participants / model
72,685 French drivers in injury-related crashes
Treatment
Dispensed oral hypnotics
Follow-up
Crashes from 2005 to 2008
Study design
Observational study using linked national databases
Funding
not stated in the source

Dispensing stands in for use.

Read the original source
Tayside: 19,386 drivers, higher accident risk on benzodiazepine days

Human study

Barbone F et al. Lancet. 1998;352(9137):1331-6. PMID 9802269.

Accident risk was higher on days of benzodiazepine use (OR 1.62, 95% CI 1.24 to 2.12; 235 drivers). The increase was significant for long-half-life anxiolytics and for short-half-life hypnotics, which were all zopiclone, and the authors advised zopiclone users not to drive.

Participants / model
19,386 drivers aged 18 and over in Tayside, UK (1,731 of them users of psychoactive drugs)
Treatment
Dispensed oral psychoactive drugs
Follow-up
First road-traffic accident between 1992 and 1995
Study design
Observational case-crossover study
Funding
not stated in the source

Observational; dispensing stands in for use.

Read the original source
12 athletes: no performance change 10 hours after zopiclone; loprazolam more hangover

Randomized controlled trial

Grobler LA et al. Clin J Sport Med. 2000;10(2):123-8. PMID 10798794.

Tests 10 hours after zopiclone 7.5 mg showed no significant change in eye-hand coordination, 30-m sprint, agility, VO2max, or treadmill time to exhaustion. The benzodiazepine loprazolam 2 mg produced more reported hangover (8 of 11 versus 3 of 11 on zopiclone) and more missed responses on eye-hand coordination. A PubMed search on 9 October 2026 for zopiclone with athlete, athletes, sport, sports, exercise, or training in title or abstract returned 20 records; this trial and the 8-athlete study were the only trials in athletes.

Participants / model
12 athletes (hangover ratings reported for 11)
Treatment
Single oral dose of zopiclone 7.5 mg, loprazolam 2 mg, or placebo
Follow-up
Psychomotor and physical performance tests 10 hours after dosing
Study design
Double-blind placebo-controlled crossover trial
Funding
not stated in the source

This favors zopiclone over one benzodiazepine in a small group of athletes. It did not study sleep disrupted by training.

Read the original source
8 athletes: better self-rated sleep, no change in performance tests

Randomized controlled trial

Tafti M et al. Prog Neuropsychopharmacol Biol Psychiatry. 1992;16(1):55-63. PMID 1557507.

Zopiclone improved self-rated sleep quality and daytime sleepiness and did not significantly change psychomotor or physical performance tests.

Participants / model
8 athletes
Treatment
Oral zopiclone 7.5 mg at night for 2 nights per session, or placebo
Follow-up
Two sessions of 2 nights each
Study design
Double-blind crossover study
Funding
not stated in the source

A small study. It did not enroll people whose sleep was disrupted by training.

Read the original source

Why is Zopiclone in A tier?

A fits a hypnotic used for short-term insomnia in the EU since the mid-1980s, still authorized in the UK and marketed in Canada, with network meta-analysis support for short-term efficacy. It is held back by consistent next-morning driving impairment, more adverse-event dropouts than placebo and eszopiclone, a label that limits use to the short term, and no US approval. The grade does not cover the supplier's stimulant and training claims.