Of 260 people who reviewed the sleep drug lemborexant online, 70 had quit it or planned to

Researchers at Rutgers read 260 online reviews of the insomnia drug lemborexant, sold as Dayvigo, and classified 70 of the reviewers as having stopped taking it or planning to. That is about one reviewer in four, and the most common reasons were sleep paralysis, vivid dreams or nightmares, and next-day grogginess. The reviews were posted between 2020 and 2023.

Save more, waste less: The Cool Down’s newsletter sends smart, simple changes that help you and the planet in your everyday life.

Subscribe to The Cool Down →

We may earn a commission if you sign up.

Lemborexant was approved in the United States in 2019 and works by blocking orexin, a brain chemical that promotes wakefulness. Roughly 30% of adults have insomnia, so a drug that quiets that signal reaches a large potential market. The question the Rutgers team asked is what happens once real patients, outside a trial, start taking it.

What 260 reviewers said

The analysis was published in the journal Sleep Medicine, in a paper with the DOI 10.1016/j.sleep.2026.109264, and reported by News-Medical on October 29, 2026. Lead author Abanoub J. Armanious, a pharmacoepidemiologist and neuropsychiatry researcher at the Rutgers Brain Health Institute, and senior author Morgan James, who also holds a post at the University of Sydney, worked with colleagues at Virginia Commonwealth University.

Ratings were polarized: the most common score was 1, followed by 10. About one-third of reviewers said the drug meaningfully improved their sleep, half reported little or no benefit, and two-thirds mentioned at least one side effect. The 70 who stopped or planned to were less likely to say the drug helped, though about as likely as the others to report poor or broken sleep.

Morgan James stressed the other side of the ledger, saying one important message of the study is that lemborexant was reported to work very well for some people, and that what stands out is how different people’s experiences with the medication can be.

The reviews put faces on the percentages. A reviewer who rated the drug 1 wrote that they felt paralyzed to move and wanted to scream but could not make a sound. Another, who stopped, said the dreams were very vivid and were the reason for quitting. At the other pole, a reviewer who rated it 10 described sleeping naturally again, the way it used to be.

Sleep paralysis, nightmares and grogginess

Sleep paralysis separated the two groups most clearly. Forty percent of reviewers who stopped or planned to stop mentioned it, compared with 15% of the others, and about one in five reviewers overall brought it up. Vivid dreams or nightmares appeared in nearly one-third of all reviews and were more common among those who quit, and next-day grogginess followed the same pattern. Armanious said some patients found certain side effects unsettling, and that a side effect can be rare and still be the reason someone discontinues treatment.

Clinical trials paint a milder picture. According to the News-Medical account, fewer than 2 in 100 trial participants had sleep paralysis and about 1 to 3 in 100 reported nightmares or abnormal dreams. The FDA-approved prescribing information bears that out: in the first 30 days, nightmares or abnormal dreams were reported by 2.2% of people on the 10 mg dose and 0.9% on both the 5 mg dose and placebo, and nightmares led 1.3% of the 10 mg group to discontinue over six months. The recommended starting dose is 5 mg taken right before bed with at least seven hours left before waking, rising to a maximum of 10 mg. The label also lists sleep paralysis, hypnagogic or hypnopompic hallucinations and cataplexy-like leg weakness as warnings, and reports somnolence or fatigue in the first 30 days at 6.9% on 5 mg and 9.6% on 10 mg, against 1.3% on placebo.

The authors offer a possible mechanism: blocking orexin may increase dream sleep, which could let dreaming and the muscle shutdown that goes with it carry over into waking moments. They present that as an explanation worth testing, not a proven one.

What a pile of reviews cannot show

The study’s limits are plain. Team members classified the 70 reviewers, about 27% of the 260, as having stopped or planning to stop by reading what each wrote, so the count reflects the researchers’ judgment of the text rather than confirmed pharmacy records of discontinuation. People with the best or worst experiences are more likely to post, so the one-in-four figure describes reviewers, not users in general, and cannot be treated as an incidence rate. Most reviewers had taken the drug for less than a month, and the group who stopped skewed toward the shortest use. Longer-term users generally rated the drug higher, and the study cannot say why. The researchers advise anyone taking a prescribed sleep medication to consult a clinician before stopping or changing it.

The work was funded by the National Institute on Drug Abuse under grants DA045765 and DA063103, along with a University of Sydney Horizon Fellowship, because the group is studying whether orexin-based drugs could treat sleep problems in psychiatric conditions, including addiction. What that research finds on side effects in those patients is not yet known.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

Save more, waste less: Subscribe to The Cool Down →

We may earn a commission if you sign up.