Eszopiclone: what it treats, how to take it, side effects
Last updated September 3, 2026.
Eszopiclone is a hypnotic - it slows activity in the brain to allow sleep. You may know it as Lunesta. It is a controlled substance (Schedule IV) with one warning that stands above the rest: complex sleep behaviors. Prescriptions for it always come from your own prescriber.
What does it treat?
Insomnia - difficulty falling asleep or staying asleep. The headline warning: some people taking eszopiclone got out of bed and drove cars, prepared and ate food, had sex, made phone calls, or sleep-walked while not fully awake, and remembered none of it. If you find out you have done anything like that - often a partner or housemate is the one who notices - stop taking it and call your doctor right away.
How do you take it?
One tablet immediately before bed, only when you can stay in bed a full night - taking it with too few hours ahead risks next-day impairment. Never with or right after a heavy, high-fat meal, which delays it. Take exactly as directed - it can be habit forming - and never combine with alcohol. If your sleep does not improve within 7 to 10 days, or worsens, or your thinking or behavior changes, call your doctor. Never stop suddenly after regular use; expect a taper.
Side effects to know
- Common: headache, daytime drowsiness, dizziness, unpleasant taste - a metallic one is the drug's signature - and dry mouth.
- Serious - call your doctor immediately or get emergency care: anxiety; and any allergic pattern - hives, rash, itching, hoarseness, difficulty breathing or swallowing, or swelling of the eyes, face, lips, tongue, throat, hands, feet, ankles, or lower legs.
Who should not take it?
Anyone who has already had a complex sleep behavior on it - that history ends the drug. Flag a history of heavy alcohol use, street drugs, or overused prescription medications, plus depression, mental illness, liver disease, and breathing problems - all shape the risk. Alcohol is out entirely during treatment. If you become pregnant, call your doctor.
When is it an emergency?
Trouble breathing or swelling of the face, tongue, or throat is a 911 call. Any discovered sleep-driving or sleep-eating episode means stop the drug and call right away. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
What are complex sleep behaviors - and how would I even know?
They are the headline warning: some people on eszopiclone got out of bed and drove, prepared and ate food, had sex, made phone calls, or sleep-walked while not fully awake - and remembered nothing after waking. You usually know because someone tells you, or because of evidence in the morning. MedlinePlus's rule: stop taking it and call your doctor right away. It is uncommon, and it is absolute - one episode ends the drug.
Why can't I take it after a late dinner?
A heavy or high-fat meal delays absorption - the drug arrives late, works late, and is still working at your alarm. MedlinePlus says not to take it with or right after a heavy, high-fat meal. The other timing rule: immediately before bed, and only when you can stay in bed a full night. Half-night dosing is how next-morning impairment happens.
Why does everything taste metallic on Lunesta?
The unpleasant taste - usually described as metallic or bitter - is on the common-effects list and is eszopiclone's calling card. It is harmless, it is worst in the morning, and it fades through the day. Water, breakfast, and brushing your teeth all help. It is the price many people happily pay for actual sleep.
Is eszopiclone habit forming?
It can be - it is a Schedule IV controlled substance, and MedlinePlus asks you to report any history of heavy drinking, street drugs, or overusing prescription medications before starting. The safeguards are the same as for any sleep drug: exact dose, immediately-before-bed use, a check-in at 7 to 10 days, and a taper rather than a sudden stop after regular use. Prescriptions come from your own prescriber who knows the whole picture.
Why is alcohol completely out while I take it?
Alcohol stacks sedation on sedation - deeper impairment, more breathing suppression, and higher odds of the sleep-behavior problem the warning is about. MedlinePlus tells you to avoid it during treatment. Not one glass at dinner, not on weekends: while eszopiclone is in your nightly routine, alcohol is paused. That is the trade the sleep is worth.
What happens if I miss a night of eszopiclone?
Nothing to catch up - it is taken only at bedtime when you need it and can stay in bed a full night. If you forgot and it is already midnight with a 6 am alarm, skip it entirely; taking it with too few hours ahead risks next-day impairment. Never take a dose during the day, and never double one.