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Zopiclone · Side effects

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Zopiclone Side Effects: Common, Serious and Long-Term

What side effects zopiclone can cause, how to manage them, and which symptoms require you to contact a pharmacist, GP, NHS 111, or emergency services.

✓ UK prescribing context✓ Plain-language answers✓ Linked medical sources
Medical information: This page provides general educational information for people in the UK. It is not a substitute for advice from a qualified healthcare professional.

Use this guide to

01UnderstandWhat Pregabalin is used for and how it works.
02CheckDosage, interactions, side effects and warnings.
03PrepareBetter questions for your GP, pharmacist or prescriber.
Pregabalin at a glanceStart with the points most relevant to you
Original productGenuine UK-licensed medicine, supplied through the authorised pharmacy process.
Common usesNerve pain, some seizures and generalised anxiety disorder.
Key cautionDrowsiness and dizziness can affect driving and balance.
Before changing treatmentSpeak with a prescriber before reducing or stopping it.
1
Quick answer: Metallic or bitter taste — most characteristic effect, very commonDrowsiness and difficulty waking the next morningDizziness or light-headednessDry mouthHeadacheNausea or upset stomachMemory impairment (anterograde amnesia)Rebound insomnia after stopping.

Common side effects

  • Metallic or bitter taste — most characteristic effect, very common
  • Drowsiness and difficulty waking the next morning
  • Dizziness or light-headedness
  • Dry mouth
  • Headache
  • Nausea or upset stomach
  • Memory impairment (anterograde amnesia)
  • Rebound insomnia after stopping

Complex sleep behaviours

Zopiclone can cause behaviours performed during sleep including sleepwalking, sleep-eating, and in rare cases sleep-driving. The person is not fully conscious and has no memory of the event. Risk is higher with alcohol, higher doses, or other CNS depressants. If this happens, stop zopiclone and contact your prescriber urgently.

Mood and behaviour effects

Some people experience paradoxical reactions — agitation, aggression, irritability, hallucinations, or disinhibition. These are more common in older adults. Rarely, depression or suicidal thoughts have been reported. Seek help promptly if your mood changes significantly.

Serious side effects requiring urgent help

  • Breathing difficulties or very slow/shallow breathing — call 999
  • Severe allergic reaction (face/throat swelling, hives, difficulty swallowing)
  • Collapse or loss of consciousness
  • Complex sleep behaviours (sleepwalking, sleep-driving)
  • Severe confusion or disorientation
  • Thoughts of self-harm or suicide — contact NHS 111 or 999

Long-term and dependence effects

Taking zopiclone beyond 2–4 weeks risks tolerance (reduced effectiveness), physical dependence, and withdrawal symptoms when stopping. See the dependence guide and the withdrawal guide.

Sources

Additional UK sources

Draft publication status: This page is prepared for a UK audience but has not yet received qualified clinical review.
Author: MediHarbour Editorial Team · Medical reviewer: To be assigned · Review date: Pending · Draft updated: 1 October 2026.
Sources should be checked against current NHS, MHRA, NICE, UK product information and peer-reviewed evidence before publication. Read our editorial policy.