Lemborexant

18.56-22.69 min

Adults taking lemborexant in SUNRISE 2 reported this much more sleep than those taking placebo. The study used sleep diaries.⁹⁰⁶

The main tradeoff

Sleepiness occurred in 8.6% and 13.1% of the studied 5-mg and 10-mg groups, compared with 1.6% on placebo. Nighttime balance, next-day driving and other sedating medicines need attention.^906,907

Newer research

The China trial missed its planned main sleep-onset threshold, then reported a positive post hoc analysis. Small studies in shift workers, cirrhosis and dementia use distinct populations and endpoints.^912,913,914

Common questions

01 How much longer did people sleep?

In SUNRISE 2, adults with insomnia reported 18.56 to 22.69 more minutes of sleep than the placebo group at six months. The trial used sleep diaries.⁹⁰⁶

02 Could I still be groggy the next morning?

Yes. The US label warns about next-day impairment and falls. Some participants taking the studied 10-mg dose had impaired driving even though the average driving-test result did not differ significantly from placebo. If you feel drowsy, avoid driving or hazardous tasks and discuss it with the prescriber.^907,908

03 What if I have to get up during the night?

Both studied doses worsened balance four hours after bedtime in a controlled safety study. The higher dose also impaired some attention and memory measures.^907,909

04 Does it help people who work nights?

Results vary. A Thai trial in 47 rotating-shift hospital workers reported better sleep and cognitive scores. A separate US trial in 29 night workers found no significant sleep-time benefit over placebo after two weeks; it did not test cognition.^910,911

05 What did research in China find?

A randomized trial in 194 adults found improvements in several sleep measures. Its planned main sleep-onset analysis missed statistical significance; a later analysis using a different transformation was positive. Separately, the uncontrolled PROEM study reported four-week remission in 61 of 200 patients in its analysis.^{912,913,914,915}

06 What matters if someone has liver disease?

The US label sets different limits for moderate and severe liver impairment. A short trial in cirrhosis found improved sleep scores, while its higher-dose group performed worse on a reaction-time test. Most participants had milder cirrhosis, and severe disease was excluded.^907,916

07 Has it been studied during breastfeeding?

A single-dose study in eight women found low transfer into breast milk. It did not measure effects in their infants. One published pregnancy and breastfeeding case also measured transfer; pregnancy and infant safety data remain sparse.^917,918,907

08 Can alcohol make the effects stronger?

Yes. In a controlled experiment, alcohol increased lemborexant exposure and the combination impaired cognitive performance more than alcohol alone. The US label warns against combining them.^919,907

09 Which medicine interactions are worth checking?

The label identifies CYP3A inhibitors and inducers, other sedating drugs, and CYP2B6 substrates such as bupropion and methadone. These can change drug exposure or treatment effect. Sedating combinations increase impairment; the US prescribing information advises against combining Dayvigo with other insomnia medicines.⁹⁰⁷

10 What do sleep paralysis and vivid dreams mean here?

They are reported effects of this drug. Sleep paralysis briefly prevents movement or speech around waking or falling asleep. The label separately warns about complex sleep behaviors such as sleepwalking or sleep-driving.⁹⁰⁷

11 Is lemborexant a peptide?

No. Lemborexant is a small-molecule prescription medicine taken as a tablet. Dayvigo is a brand name.⁹⁰⁷

12 How does it help with sleep?

It blocks the two orexin receptors, which help sustain wakefulness. Its US indication covers trouble falling asleep, staying asleep, or both in adults.⁹⁰⁷

13 How long have people taken it in trials?

SUNRISE 2 followed treatment for twelve months. The placebo comparison lasted six months; participants initially given placebo then switched to lemborexant.^906,920

14 What happened when people stopped it?

A SUNRISE 2 analysis followed 655 study completers for two weeks after treatment ended. Its questionnaire found no withdrawal signal, and sleep improvements generally persisted during that follow-up.⁹²¹

15 Can it be misused?

Yes. The US label describes abuse potential. In an experiment involving people who used sedatives recreationally, lemborexant produced higher drug-liking ratings than placebo.^907,922

16 What if someone has sleep apnea?

Short crossover studies included 39 people with mild sleep apnea and 33 with moderate or severe sleep apnea. Average breathing measures did not significantly worsen with lemborexant over eight treatment nights. These studies leave longer-term breathing safety unresolved.^923,924,907

17 Has it been studied in COPD?

Yes. A crossover trial in 30 people with moderate or severe COPD measured breathing over eight treatment nights. Average oxygen saturation and apnea measures were not worsened compared with placebo.⁹²⁵

18 Does it help chronic pain?

Pain scores did not improve significantly in a small chronic-pain study, although sleep improved. Five of the 26 people who started treatment stopped because of side effects and were excluded from the final analysis.^926,927

19 Can it cause nightmares?

Yes. Nightmares are a reported side effect. A Japanese hospital review found them in 8.0% of 327 psychiatric patients; the frequency varies across study populations.^928,929,907

20 What if I take clozapine?

One published case reported higher clozapine levels and oversedation after lemborexant was added. Both improved after it was withdrawn. That interaction is worth raising with the clinician managing clozapine.⁹³⁰

21 Could it help if I keep waking up to pee?

An uncontrolled four-week study in 32 people found fewer nighttime bathroom trips and better sleep scores. Three people reported mild sleepiness. A controlled trial would give a clearer answer.⁹³¹

22 Does it prevent delirium in hospital?

Evidence is still uncertain. Some hospital observations found lower delirium rates, while a Japanese matched comparison found no significant difference from other sleep medicines. Controlled prevention studies are still underway.^{932,933,934,935}

23 Did the China trial meet its main goal?

Its planned main analysis missed the trial's statistical threshold: p=0.0585. After treatment assignments were revealed, researchers added a different analysis because the original transformation had not adequately handled the data distribution; that analysis gave p=0.0096. Both results belong in the account of this trial.^913,914,912

24 Has it been compared with Ambien?

SUNRISE 1 compared lemborexant with extended-release zolpidem and placebo in 1,006 older adults with insomnia. Lemborexant improved sleep onset and maintenance, including wakefulness later in the night compared with the studied zolpidem formulation.⁹³⁶

25 Does it improve memory?

A small Thai shift-worker trial reported improvements on cognitive tests. Other studies have measured daytime functioning and brain-imaging markers. Long-term memory benefits and dementia prevention remain unproven.^{910,937,938,907}

26 Does it work in older adults?

Older adults were studied directly in SUNRISE 1. A separate analysis of 262 SUNRISE 2 participants aged 65 or older also found improvements in reported sleep. The tradeoff includes morning sleepiness, balance and falls.^936,939,907

27 Is it better than Quviviq or Belsomra?

There is no clear winner from head-to-head trials. Most published rankings compare separate studies, with different participants, doses and measures of sleep.^940,941,942

28 Does it lower the risk of falling?

Falls remain a concern. A Japanese hospital study recorded 68 falls among 1,324 people taking lemborexant or suvorexant. It did not establish that lemborexant lowered the risk. The US label warns about falls, especially in older adults.^{907,943,909,944}

29 Why do people talk about it clearing amyloid?

Mouse experiments found changes in amyloid deposits and the brain cells that help remove them. A small human study measured indirect MRI markers of fluid movement; amyloid removal in people remains unproven.^945,946,938

30 Does adding yokukansan make it work better?

A Japanese hospital study found no significant extra improvement from adding yokukansan over two weeks. People in the combination group started with worse insomnia, which complicates the comparison.⁹⁴⁷

31 Can it help someone switch off a benzodiazepine?

Small Japanese studies have followed people changing to lemborexant. In one, 26 of 33 patients stayed on it for 12 weeks while reducing their previous medicine. Another found different results for adding it versus switching. These were observational studies. Changing treatment needs a plan for the original drug, with follow-up for sleep and side effects.^948,949

32 Does a higher dose give better sleep?

Both studied doses improved sleep in SUNRISE 2. At six months, the 5-mg and 10-mg groups reported about 19 and 23 extra minutes of sleep versus placebo. Sleepiness occurred in 8.6% and 13.1%, compared with 1.6% on placebo. The higher dose brought more sleepiness and more treatment stops from side effects.^906,907

33 Why am I still waking up during the night?

Lemborexant can reduce time spent awake without eliminating every awakening. In SUNRISE 2, the studied groups reported about 13 to 17 fewer minutes awake after falling asleep than placebo at six months. Persistent awakenings deserve a review of the treatment and other causes of disrupted sleep.^906,907

34 Should it work right away, or does it take weeks?

SUNRISE 2 found sleep benefits during the first seven nights. Individual responses vary. The US label calls for reassessment if insomnia worsens or has not improved within 7 to 10 days. There is no fixed adjustment period that everyone needs to push through.^906,907

35 What if it still takes me ages to fall asleep?

The trial averages include people who responded differently. Food near the dose can delay its effect, and other medicines can change drug exposure. If sleep is still poor, the prescriber can review timing, interactions and other sleep problems before changing treatment. The US label limits use to once per night.^906,907

36 Do food and bedtime timing matter?

Yes. Taking it with or soon after a meal can delay sleep onset. The US label places the dose immediately before bed, with at least seven hours available for sleep. Taking it earlier to offset a meal can leave someone impaired while still up and active.⁹⁰⁷

37 Can it affect my mood?

The label warns about worsening depression and suicidal thoughts. New mood or behavior changes need prompt review. Contact the prescriber right away for worsening depression or thoughts of suicide; seek emergency help if there is an immediate risk of harm.⁹⁰⁷

38 Where can it be prescribed, and what will it cost?

Dayvigo has approval records in the US, Japan, Canada, India, Australia, New Zealand and Brazil. Availability, dispensing rules and coverage vary by country. A local pharmacist can check the current price and stock for a prescription.^{907,950,951,952,953,954,955}

39 What about sleep habits or CBT-I?

Cognitive behavioral therapy for insomnia, or CBT-I, treats the thoughts and habits that keep insomnia going. AASM recommends it for chronic insomnia. Its 2026 guideline conditionally favors CBT-I with medication over medication alone, based on low-certainty evidence from older sleep medicines. Basic sleep-hygiene advice alone has weaker support.^956,957

40 Can the effect wear off with regular use?

Sleep improvements persisted through twelve months in people continuing lemborexant in SUNRISE 2. The placebo comparison ended at six months. A return of poor sleep needs reassessment; increasing the dose or taking breaks to reset tolerance has not been established by those results.^920,907

41 What if I do things in my sleep and do not remember them?

Sleepwalking, sleep-driving, cooking or other activities while not fully awake are serious reported effects. The US label says to stop Dayvigo immediately and contact the prescriber if this happens. These events can occur after the first dose or later, including without alcohol or other sedatives.⁹⁰⁷

42 What did the Alzheimer's sleep-rhythm trial find?

A four-week study treated 62 people with Alzheimer's disease and irregular sleep-wake rhythms. Its main analyses found no significant dose-response trend for sleep or wake efficiency. Some exploratory sleep measures improved. Memory benefit was not established.^958,959

43 Could it help reflux as well as sleep?

A small study followed 16 people with reflux and insomnia for four weeks. Its main reflux-symptom score did not improve significantly. Regurgitation improved on a secondary measure, while objective reflux measurements were unchanged. The study had no comparison group.^960,961

44 Can it ever make sleep or behavior worse?

The US label calls for reassessment when insomnia worsens or new behavior changes appear. FDA also listed a possible paradoxical-reaction signal for orexin sleep medicines, including Dayvigo. That notice records its status as of September 2024; it gives no reliable rate or confirmed causal explanation.^907,962