Dayvigo Side Effects

Generic name: lemborexant

Medically reviewed by Philip Thornton, DipPharm. Last updated on Mar 30, 2025.

Note: This document provides detailed information about Dayvigo.

Applies to lemborexant: oral tablet Side Effects associated with lemborexant. Some dosage forms listed on this page may not apply specifically to the brand name Dayvigo.

Applies to lemborexant: oral tablet.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to check for unwanted effects.

If you think you need to take lemborexant (the active ingredient contained in Dayvigo) for more than 7 to 10 days, be sure to discuss it with your doctor. Insomnia that lasts longer than this may be a sign of another medical problem.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

This medicine may cause some people, especially older persons, to become drowsy, dizzy, lightheaded, clumsy or unsteady, or less alert than they are normally, which may lead to falls, fractures, or other injuries. Even though lemborexant is taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

If you develop any unusual and strange thoughts or behavior while you are using lemborexant, be sure to discuss it with your doctor. Some changes that have occurred in people using this medicine are like those seen in people who drink alcohol and then act in a manner that is not normal. Other changes may be more unusual and extreme, such as confusion, worsening of depression, hallucinations (seeing, hearing, or feeling things that are not there), suicidal thoughts, and unusual excitement, nervousness, or irritability.

This medicine may cause you to do things while you are still asleep that you may not remember the next morning. You could drive a car, sleepwalk, have sex, make phone calls, or prepare and eat food while you are asleep or not fully awake. Tell your doctor right away if any of these things occur.

This medicine may cause sleep paralysis (temporary inability to move or talk for up to several minutes while you are going to sleep or wake up) or have cataplexy-like symptoms (temporary weakness in your legs). Tell your doctor right away if you have these symptoms while you are using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Serious side effects of Dayvigo

Along with its needed effects, lemborexant may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking lemborexant:

Other side effects of Dayvigo

Some side effects of lemborexant may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to lemborexant: oral tablet.

General adverse events

The most commonly reported side effects included somnolence, fatigue, headache, abnormal dreams and/or nightmares.^[Ref]

Nervous system

• Very common (10% or more): Somnolence (up to 10.5%)
• Common (1% to 10%): Headache, sleep paralysis
• Frequency not reported: Cataplexy-like symptoms, lethargy^[Ref]

Psychiatric

• Common (1% to 10%): Abnormal dreams, nightmare
• Frequency not reported: Complex sleep behavior, hypnagogic hallucinations, suicidal ideation, worsening of depression^[Ref]

Other

• Common (1% to 10%): Fatigue
• Frequency not reported: Sluggishness^[Ref]

See also:

Frequently asked questions

• Is Dayvigo addictive?
• What are the strongest sleeping pills?

Further information

Dayvigo side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer