Eszopiclone Side Effects: What You Need to Know

Eszopiclone (brand name Lunesta) is an effective prescription sleep medication, but like all drugs, it comes with potential side effects. Some are mild and temporary. Others are serious and require immediate medical attention.

This guide breaks down the most common and serious side effects of Eszopiclone based on FDA labeling, explains who may be at higher risk, and tells you exactly when to call your doctor.

What Is Eszopiclone?

Eszopiclone is a non-benzodiazepine sedative-hypnotic (sometimes called a "Z-drug") prescribed for insomnia. It works by enhancing the activity of GABA, a brain chemical that promotes relaxation and sleep. It's available as a generic and under the brand name Lunesta in 1 mg, 2 mg, and 3 mg tablets. For a deeper look at how this medication works, see our guide on how Eszopiclone works.

Common Side Effects

Most people who take Eszopiclone experience mild side effects, especially during the first few days of treatment. These often improve as your body adjusts to the medication.

• Unpleasant or metallic taste — This is the most frequently reported side effect, affecting up to 34% of patients taking the 3 mg dose. Many people describe it as a bitter or metallic taste that lingers into the morning. It's harmless but can be bothersome.
• Headache — Reported in up to 21% of patients. Usually mild and manageable with over-the-counter pain relievers.
• Daytime drowsiness — Feeling sleepy or groggy the next morning is common, especially at higher doses. This is why Eszopiclone should be taken only when you can devote 7-8 hours to sleep.
• Dizziness — Some patients feel lightheaded, particularly when getting up quickly. Move slowly when standing.
• Dry mouth — A common side effect that usually improves with hydration.
• Upper respiratory infection symptoms — Cold-like symptoms such as sore throat or stuffy nose have been reported in clinical trials.
• Abnormal or vivid dreams — Some people experience unusually vivid or strange dreams.

Serious Side Effects

While uncommon, Eszopiclone can cause serious side effects that require immediate medical attention. The FDA has issued a boxed warning — the most serious type of warning — for one of these.

Complex Sleep Behaviors (Boxed Warning)

This is the most important safety concern with Eszopiclone. Some patients have experienced:

• Sleepwalking
• Sleep-driving
• Making phone calls, eating, or having conversations while not fully awake

These behaviors can result in serious injuries and, in rare cases, death. Patients often have no memory of these events. If you or someone in your household notices any complex sleep behavior, stop taking Eszopiclone immediately and contact your doctor.

Severe Allergic Reactions

In rare cases, Eszopiclone can cause anaphylaxis or angioedema (severe swelling of the face, tongue, or throat). Seek emergency medical care if you experience:

• Difficulty breathing or swallowing
• Swelling of your face, lips, tongue, or throat
• Hives or severe rash

Next-Day Impairment

Even at recommended doses, Eszopiclone can impair alertness, coordination, and driving ability the morning after taking it. This risk is higher if you take the 3 mg dose or don't get a full 7-8 hours of sleep.

Worsening Depression or Suicidal Thoughts

Eszopiclone may worsen depression or trigger suicidal thinking in some patients. Tell your doctor right away if you notice mood changes, increased anxiety, or thoughts of self-harm.

Memory Impairment

Some patients report amnesia — difficulty remembering things that happened after taking the medication. This is more likely at higher doses.

Dependence and Withdrawal

As a Schedule IV controlled substance, Eszopiclone carries a risk of physical and psychological dependence, especially with long-term use. Stopping suddenly after extended use can cause withdrawal symptoms including anxiety, rebound insomnia, nausea, and muscle cramps. Always taper under your doctor's guidance.

Side Effects in Specific Populations

Older Adults (65+)

Elderly patients are more sensitive to Eszopiclone's sedative effects. The recommended starting dose is 1 mg. Older adults face a higher risk of falls, next-day drowsiness, and cognitive impairment.

People with Liver Problems

Eszopiclone is processed by the liver. Patients with severe hepatic impairment should not exceed 2 mg, as the drug stays in the body longer and side effects become more likely.

People with Respiratory Conditions

Eszopiclone should be used with caution in patients with COPD, sleep apnea, or other breathing problems, as it can depress respiratory function.

Pregnant or Nursing Women

Eszopiclone is not recommended during pregnancy. If you're pregnant, planning to become pregnant, or breastfeeding, talk to your doctor about safer alternatives.

How to Manage Common Side Effects

Many side effects can be minimized with simple strategies:

• Metallic taste: Try brushing your teeth or using mouthwash before bed. Some patients find that keeping water by the bed helps. The taste often becomes less noticeable over time.
• Morning drowsiness: Make sure you're allowing a full 7-8 hours for sleep. Ask your doctor about lowering your dose if grogginess persists.
• Dizziness: Get up slowly from bed. Avoid activities that require alertness until you know how the medication affects you.
• Dry mouth: Stay hydrated. Sugar-free gum or lozenges can also help.
• Headache: Over-the-counter pain relievers like acetaminophen usually help. Tell your doctor if headaches persist.

When to Call Your Doctor

Contact your healthcare provider if you experience:

• Any complex sleep behavior (sleepwalking, sleep-driving, or doing activities while not fully awake)
• Signs of an allergic reaction (swelling, hives, difficulty breathing)
• Worsening depression or suicidal thoughts
• Memory problems that concern you
• Side effects that don't improve after the first week or that interfere with your daily life

Go to the emergency room if you have difficulty breathing, severe swelling, or any sign of a serious allergic reaction.

Final Thoughts

Most people tolerate Eszopiclone well, and the most common side effects — like the metallic taste and morning grogginess — tend to be manageable. But it's important to know the serious risks, especially complex sleep behaviors and allergic reactions, so you can act quickly if they occur.

If you have questions about whether Eszopiclone is right for you, talk to your doctor. And if you're ready to fill your prescription, Medfinder can help you find Eszopiclone in stock at a pharmacy near you.