About one in four reviewers taking the insomnia drug lemborexant reported stopping or planning to quit the medication, frequently driven by vivid nightmares, next-day grogginess, and distressing episodes of sleep paralysis, according to a study published in the journal Sleep Medicine.
When lemborexant was approved in the U.S. in 2019 as a prescription treatment for trouble falling or staying asleep, it arrived as part of the newest class of sleep medications. Instead of broadly sedating the entire brain like older sleeping pills, these newer pharmaceuticals operate by blocking chemical messenger signals from orexin, a natural compound that keeps people awake. Clinical trials established that the medication, sold under the brand name Dayvigo, helped patients fall asleep faster and stay asleep longer than a placebo.
Yet clinical trials often miss the full picture of how a medication feels in everyday life. To investigate why patients abandon the treatment, researchers from the Rutgers Brain Health Institute, Virginia Commonwealth University, and the University of Sydney examined 260 online reviews of lemborexant posted between 2020 and 2023. The analysis revealed a stark divide in patient experiences.
Sharp Divides in Patient Ratings and Side Effect Reports
User ratings for the medication split dramatically into two extremes. The most common score given by reviewers was a 1 out of 10, followed by a 10 out of 10. Roughly a third of the reviewers reported that the medication meaningfully improved their sleep.
For others, however, the experience was profoundly unsettling. The study team classified 70 of the 260 reviewers as having stopped or planning to stop taking the drug. While these individuals complained of broken or poor sleep at rates similar to other reviewers, they experienced distinct, disruptive side effects that drove them away from the treatment.
Felt paralyzed to move. Wanted to scream and could not make a sound. Was able to touch my husband’s arm and waken him. He said he never saw such terror in my eyes.
Reviewer, via News-Medical
Sleep Paralysis and Vivid Nightmares Dominate Discontinuation Reasons
That reviewer was describing sleep paralysis, a temporary state of being awake but unable to move or speak. The study found that sleep paralysis appeared in 40% of reviews written by people who stopped or planned to stop taking lemborexant, compared with 15% among the remaining reviewers.
Vivid dreams, nightmares, and next-day grogginess were also more common among those who quit. One reviewer noted, The dreams [nightmares] are VERY vivid and that’s the reason I can no longer take this medication.
Researchers suggest a physiological mechanism for these occurrences: blocking orexin can increase dreaming sleep, which may allow muscle shutdown and intense dream states to spill over into waking moments. Not every intense dream was viewed negatively, though; one reviewer who rated the medication a 9 out of 10 stated they looked forward to wild crazy dreams.
Most reviewers who decided to stop the medication had used it for less than a month. At the same time, the research team noted that longer-term users generally assigned higher ratings to the drug.
Clinical Trial Data Versus Real-World Patient Tolerability
The study highlights a fundamental gap between controlled clinical trials and unsupervised real-world usage. In lemborexant’s two main clinical trials, which tracked everyone enrolled, fewer than 2 in 100 people experienced sleep paralysis, and roughly 1 to 3 in 100 reported nightmares or abnormal dreams.
A clinical trial can tell you how often side effects occur. It is less equipped to tell you how much that side effect matters to the person living it. A side effect can be rare and still be the reason someone discontinues treatment.
Abanoub J. Armanious, Rutgers Brain Health Institute
Study authors emphasized that online reviews naturally skew toward extreme experiences, as individuals with exceptionally good or terrible outcomes are the most motivated to post. Consequently, the review data cannot establish exact occurrence rates across the general population of users.
Researchers stress that patients should not be alarmed by these findings, but rather use them to set realistic expectations with their healthcare providers. Anyone currently taking a prescribed sleep medication is advised to consult a clinician before making any changes or stopping treatment.