Zopiclone Dosage and Duration: 3.75 mg, 7.5 mg and the Limits That Matter

Zopiclone has one of the narrowest dose ranges of any medicine in regular use. Two strengths cover essentially every adult prescription written for it, and the difference between them is a single halving. That simplicity is easy to miss, because the drug is also one of the most misunderstood sleep medicines in circulation.

This guide sets out the licensed doses, how long zopiclone is meant to be taken for, what the comparative trial evidence actually shows against the alternatives, and why stopping it needs a plan agreed before you start.

Zopiclone is a prescription medicine everywhere it is licensed. Nothing below replaces a prescriber who knows your liver function, your other medicines and your history with sedatives.

The two licensed zopiclone strengths

Zopiclone is licensed in the United Kingdom, Australia, Canada and across most of Europe. Wherever it is approved, the dosing instruction is close to identical.

Dose	Who it is for	How it is taken
7.5 mg	Standard adult dose	One tablet, immediately before bed
3.75 mg	Adults over 65, liver impairment, kidney impairment, anyone unusually sensitive to sedatives	One tablet, immediately before bed

There is no third step. In older adults, 3.75 mg is the starting dose and may be raised to 7.5 mg only if the lower dose proves inadequate and is tolerated well. Current prescribing information in the UK, Australia and Canada caps the adult dose at 7.5 mg once daily. It is a ceiling, not a midpoint on a ladder.

Two practical consequences follow. First, zopiclone is a once nightly medicine, never a divided dose. Second, a person prescribed 7.5 mg should be taking 7.5 mg irrespective of what tablet strengths happen to be available, and splitting or doubling to reach a different number is a prescriber decision rather than a personal one.

Zopiclone is not an FDA approved medicine in the United States

This trips up a lot of people who read UK or Australian sleep advice and then look for the drug at home. Zopiclone has never held FDA approval. What the United States approved instead is eszopiclone, marketed as Lunesta, which is the single active half of the zopiclone molecule isolated on its own.

So the practical position by market looks like this.

Market	Zopiclone	Eszopiclone
United Kingdom	Licensed, prescription only, Class C controlled drug	Not licensed
Australia	Licensed, Schedule 4 prescription only	Not licensed
Canada	Licensed, prescription only	Not marketed
United States	Not approved	Approved, Schedule IV controlled substance

If you have been reading about a 3 mg dose, you were reading about eszopiclone. If you have been reading about a 7.5 mg dose, you were reading about zopiclone. The two numbers are not interchangeable, and the relationship between them is covered in our guide to zopiclone versus eszopiclone.

How long zopiclone is meant to be used

The duration limit is the part most often ignored, and it is the part that causes most of the trouble.

Zopiclone is licensed for short term treatment of insomnia. In UK practice that means a course of no more than four weeks, including the time spent reducing the dose at the end. Guidance is more restrictive still for people who have not first tried non drug approaches, because cognitive behavioural therapy for insomnia is the first line treatment in every major European and North American guideline, with medication positioned as a second option.

Two things happen when a four week medicine is taken for eight months. Tolerance develops, so the same tablet produces less sleep than it used to. And physical dependence develops, so stopping produces rebound insomnia that feels like proof the drug was working, when it is actually withdrawal.

A short course means three things in practice:

• An agreed end date at the point of the first prescription, not decided later
• Intermittent dosing where possible, for example three or four nights a week rather than every night
• A written reduction plan, because the taper is part of the four weeks and not an extra month on top

What the comparative evidence actually shows

The largest synthesis of insomnia drug trials to date pooled 170 randomised trials covering 47,950 participants, with 154 double blind trials and 44,089 participants eligible for the network meta analysis itself. For short term treatment, benzodiazepines, doxylamine, eszopiclone, lemborexant, seltorexant, zolpidem and zopiclone all beat placebo, with standardised mean differences between 0.36 and 0.83.

The more useful finding is the second tier comparison. Benzodiazepines, eszopiclone, zolpidem and zopiclone outperformed melatonin, ramelteon and zaleplon, with standardised mean differences of 0.27 to 0.71. In plain terms, zopiclone genuinely works better than melatonin for short term insomnia, and the size of that advantage is moderate rather than dramatic.

What the same body of evidence does not show is a long term advantage. The trials that support zopiclone are short. Efficacy data past a few weeks is thin for the whole Z drug class, which is exactly why the licensing is written the way it is.

Timing, food and the eight hour rule

Zopiclone reaches peak blood levels quickly and has an elimination half life of roughly five hours in healthy adults. That extends in older people and in anyone with reduced liver function, which is the pharmacological reason behind the lower dose in those groups rather than simple caution.

Three timing rules follow from that half life:

• Take it immediately before lying down, not an hour before as a wind down ritual. Onset is fast, and the window between taking the tablet and being unsteady on your feet is short.
• Allow a full night. Plan for at least seven to eight hours in bed before you need to be alert. Taking zopiclone at 3am for a 7am start is a recipe for next day impairment.
• Avoid a heavy meal immediately before the dose. Food slows absorption, which pushes the peak later into the night and can leave more drug on board in the morning.

Side effects worth knowing before the first tablet

The signature zopiclone side effect is a persistent bitter or metallic taste. It is not dangerous, it is very common, and it is the single most frequent reason people stop the drug. It often lingers into the following day.

Beyond taste, the effects that matter clinically are:

• Next day drowsiness and slowed reaction time, worst in the first few nights and in anyone taking 7.5 mg who should have been on 3.75 mg
• Unsteadiness and falls, the dominant safety concern in older adults and the reason the dose is halved for them
• Amnesia for events after taking the tablet, particularly if the person stays awake rather than going straight to bed
• Complex sleep behaviours, meaning sleepwalking, sleep eating, making phone calls or attempting to drive while not fully awake and with no memory of it afterwards
• Dry mouth, headache and daytime fatigue

Complex sleep behaviours deserve particular attention. The class carries a boxed warning in the United States for exactly this, and the instruction is unambiguous: a single episode means the drug is stopped permanently, not reduced. These events have caused serious injury and death, and the risk rises sharply when the drug is combined with alcohol or another sedative.

Next day driving and legal exposure

In the United Kingdom, zopiclone is one of the drugs covered by the drug driving offence, which sets specified blood limits independent of whether you feel impaired. Holding a valid prescription and taking the drug as directed is a defence, but only if your driving is not actually impaired at the time.

The practical rule is to treat the morning after a 7.5 mg dose the way you would treat the morning after alcohol. If you woke earlier than planned, if you took the tablet late, or if this is one of your first few nights on it, do not drive.

Who should not take a standard dose

Zopiclone is contraindicated or requires a different approach in several groups:

• Severe respiratory insufficiency or sleep apnoea, because sedatives reduce the drive to breathe and blunt arousal from apnoeic episodes
• Severe liver impairment, where clearance is prolonged and 3.75 mg is the starting point at most
• Myasthenia gravis
• A history of dependence on alcohol, benzodiazepines or other sedatives, where the risk of the same pattern repeating is high
• Pregnancy and breastfeeding, where zopiclone passes into breast milk and use near delivery has been linked to sedation and withdrawal in the newborn
• Anyone under 18, for whom zopiclone is not licensed

Depression is a special case rather than a contraindication. Insomnia is frequently a symptom of an untreated mood disorder, and treating the sleep alone leaves the actual problem in place. Sedatives can also disinhibit, so a prescriber will normally want the underlying condition assessed first.

Combinations that change the risk

The additive sedation risk is the one to take seriously. Zopiclone combined with any of the following produces more impairment than either alone:

• Alcohol, which is the most common and most underestimated combination
• Opioids, including codeine and tramadol, where the combination adds a respiratory depression risk on top of sedation
• Benzodiazepines and other Z drugs
• Gabapentinoids such as pregabalin, which carry their own sedation profile as set out in our pregabalin side effects breakdown
• Sedating antihistamines, including several sold without prescription as sleep aids
• Muscle relaxants and sedating antidepressants

Metabolism matters too. Zopiclone is cleared largely through CYP3A4, so strong inhibitors of that enzyme, including clarithromycin, ketoconazole, itraconazole and ritonavir, raise zopiclone levels. Strong inducers such as rifampicin, carbamazepine and St John's wort push levels down and can make a standard dose stop working.

Coming off zopiclone

Stopping abruptly after regular use produces rebound insomnia that is typically worse than the original problem for a few nights, along with anxiety, irritability, tremor and sweating. After long or high dose use, abrupt withdrawal from this drug class can trigger seizures.

A 2025 European expert consensus on switching and deprescribing hypnotics reviewed the evidence and recommended that discontinuation of benzodiazepines and Z drugs be gradual, with dose reductions of 10 to 25 percent each week. The same work found that cognitive behavioural therapy for insomnia, and certain alternative agents used as a cross taper, made gradual discontinuation more achievable, and that the schedule can be slowed whenever a step proves difficult.

Applied to zopiclone, a realistic reduction looks like this:

Stage	Approach
Weeks 1 to 2	Move from 7.5 mg every night to 7.5 mg on five nights, with two drug free nights placed where the next day is least demanding
Weeks 3 to 4	Step the dose down to 3.75 mg on dosing nights
Weeks 5 to 6	Reduce dosing nights to three, then two
Week 7 onward	Stop, with sleep hygiene and behavioural techniques carrying the load

Two rules apply throughout. Never remove a step and add another in the same week. And if a step is genuinely difficult, hold at that level for longer rather than reversing, because repeatedly going up and down is harder than a slow flat line.

Legal status by market

• United Kingdom: Class C controlled drug, Schedule 4 Part I. Prescription only, and prescriptions carry stricter requirements than an ordinary prescription only medicine.
• Australia: Schedule 4 prescription only medicine.
• Canada: Prescription only medicine.
• United States: Not approved for marketing. Eszopiclone is the approved equivalent and is a Schedule IV controlled substance.

A valid prescription is required in every market where zopiclone is licensed. Any site offering it with no prescription and no questions asked is operating outside the rules that apply in your country, whatever the page says. Our guides on verifying a legitimate online pharmacy and what WHO GMP certification means cover what to check before ordering anything.

What to raise with your prescriber

• Whether 3.75 mg is the right starting point given your age, liver function and other sedating medicines
• An agreed stop date and written reduction plan, set at the first prescription rather than at the end
• Whether intermittent dosing on three or four nights a week would work instead of nightly use
• Whether cognitive behavioural therapy for insomnia is available to you, since it is the first line treatment and the only one with durable effect after it is stopped
• Whether your insomnia might be a symptom of sleep apnoea, depression, chronic pain or a thyroid problem that the tablet will not touch
• Whether daytime sleepiness rather than night time wakefulness is the real complaint, since that points towards a different class of medicine entirely, as covered in our guide to modafinil versus armodafinil

The insomnia treatment page sets out where zopiclone sits against the other options, and the products we stock at licensed strengths include zopiclone 7.5 mg and zopiclone 3.75 mg.

References

• De Crescenzo F et al. Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a systematic review and network meta-analysis. PMID 35843245
• Palagini L et al. Clinical practice guidelines for switching or deprescribing hypnotic medications for chronic insomnia: results of European neuropsychopharmacology and sleep expert's consensus group. PMID 39923608
• Rosenberg R et al. Comparative efficacy of lemborexant and other insomnia treatments: a network meta-analysis. PMID 34121443
• FDA prescribing information for eszopiclone tablets, boxed warning (Complex Sleep Behaviors), sections 2.1 to 2.5 and 4
• UK Medicines and Healthcare products Regulatory Agency summary of product characteristics for zopiclone tablets

Medical disclaimer: this article is for information only and is not medical advice. Zopiclone is a prescription medicine and a controlled drug in several countries. Dose, duration and any reduction plan must be set by a licensed prescriber who knows your medical history. Do not start, change or stop zopiclone on the basis of anything written here.