It blocks the mechanism that keeps you awake, not the sleep itself
For the millions of Brazilians who lie awake in the dark, medicine has long offered a blunt instrument — chemicals that force the brain into unconsciousness, often at the cost of dependence and withdrawal. Brazil's health regulator Anvisa has now approved lemborexant, a drug that takes a quieter path: rather than compelling sleep, it silences the hormone that insists on wakefulness, allowing rest to arrive on its own terms. The approval, published in April, introduces a new class of sleep medicine to the country and reopens a question that has shadowed insomnia treatment for decades — whether relief can be offered without the burden of dependency.
- Nearly half of all Brazilians report insomnia, and the drugs most commonly prescribed carry real risks of dependence, tolerance, and withdrawal — a trade-off patients and doctors have long had to accept.
- Lemborexant disrupts that calculus by targeting orexin, the hormone that keeps the brain alert, rather than sedating it directly — a mechanism that sidesteps the dependency pathways of older sleep drugs.
- A landmark Oxford study ranked lemborexant among the most effective and tolerable insomnia treatments available, though researchers flagged that its long-term safety profile is still not fully understood.
- The drug has been available in the United States since 2019 at roughly $300 per month, and Brazil's pricing board must now decide whether this new option will be financially reachable for the patients who need it most.
Brazil's health regulator Anvisa has approved lemborexant — sold as Dayvigo by Japanese pharmaceutical company Eisai — as a new treatment for insomnia, with the decision published in the Official Gazette in April. What sets it apart from the medications most Brazilians currently use is not just its novelty, but its logic: where existing drugs like zolpidem and zopiclona force the brain into sleep by acting on GABA receptors, lemborexant works by blocking orexin, the hormone responsible for keeping a person awake. The result is sleep that arrives more naturally — and a significantly lower risk of the dependence, tolerance, and withdrawal that have made long-term use of older medications so problematic.
The scientific case for this approach is substantial. A 2022 Oxford University study published in The Lancet evaluated 36 insomnia treatments and found lemborexant among the strongest performers for efficacy, patient retention, and tolerability — in both short- and long-term scenarios. Researchers did note that long-term safety data remains inconclusive, a caveat that will matter as the drug enters broader use in Brazil.
The scale of the problem it addresses is hard to overstate. A 2023 survey by the Oswaldo Cruz Foundation found that 72 percent of Brazilians experience some form of sleep disorder, with 45 percent reporting insomnia and 15 percent living with the chronic variety. Neurologist Lucio Huebra of the Brazilian Sleep Academy notes that lemborexant belongs to an entirely new class in Brazil — orexin receptor antagonists — though similar drugs have been available in the United States and Europe for years.
The remaining question is access. In the US, monthly treatment costs around $300 — approximately 1,600 reais at current exchange rates. Brazil's drug pricing board will set the local price, and that decision will determine whether this quieter, gentler approach to sleeplessness becomes a real option for the patients who need it most. Neurologist Dalva Poyares of Unifesp reminds that cognitive-behavioral therapy remains the gold standard, and that medication — when necessary — should be used at the lowest effective dose and discontinued when possible. Lemborexant does not change that principle; it simply gives doctors a more forgiving tool when medication cannot be avoided.
Brazil's health regulator has cleared a new insomnia medication that works differently from the drugs currently prescribed to millions of Brazilians struggling with sleep. Lemborexant, sold under the brand name Dayvigo by Japanese pharmaceutical company Eisai, received approval from Anvisa and was published in the Official Gazette on April 3rd. The distinction matters because it offers a fundamentally different approach to the problem of sleeplessness—one that carries substantially lower risk of dependence than the medications doctors have relied on for years.
The drugs now widely used in Brazil—zolpidem, zopiclona, and eszopiclona, collectively known as "Z-drugs"—work by inducing sleep directly. Lemborexant takes the opposite path. Instead of pushing the brain toward sleep, it blocks the mechanism that keeps a person awake. Specifically, it targets orexin, a hormone responsible for maintaining alertness. By silencing that signal, the medication allows sleep to occur naturally rather than forcing it chemically. This distinction is not merely academic. Because lemborexant does not act on GABA, the neurotransmitter that Z-drugs target, it carries far less potential for dependence, tolerance, and withdrawal symptoms—problems that have made existing treatments problematic for long-term use.
The evidence supporting this approach comes from a 2022 Oxford University study published in The Lancet, which analyzed 36 different insomnia treatments. Lemborexant and eszopiclona emerged as the strongest performers across three critical measures: efficacy, acceptability (how many patients stayed with the treatment), and tolerability (how many quit due to side effects). Both medications showed superior results in both short-term and long-term treatment scenarios. One caveat: the researchers flagged that lemborexant's long-term safety data remained inconclusive, a limitation worth noting as the drug enters wider use.
Insomnia in Brazil is far more than a minor inconvenience. A 2023 Oswaldo Cruz Foundation survey found that 72 percent of Brazilians experience some form of sleep disorder, with 45 percent reporting insomnia specifically and 15 percent suffering from chronic insomnia. Globally, research estimates that 16.2 percent of the adult population experiences clinically significant insomnia, with 7.9 percent dealing with severe cases. When insomnia occurs at least three times weekly for three consecutive months, it crosses into chronic territory—a condition that can persist for an average of three years and affect up to 74 percent of patients throughout a given year. The toll extends beyond mere tiredness: fatigue, irritability, difficulty concentrating, memory lapses, and a pervasive sense of exhaustion degrade quality of life substantially.
Lucio Huebra, a neurologist and member of the Brazilian Sleep Academy, explains that current treatment options fall into three main categories. Benzodiazepine agonists—the Z-drugs—represent one approach. Sedating antidepressants like doxepine and trazodone form another. Melatonin receptor agonists like ramelteon comprise the third. Lemborexant belongs to an entirely separate class: orexin receptor antagonists. Other medications in this category, such as suvorexant and daridorexant, are already sold in the United States and Europe, but lemborexant is new to Brazil.
The practical question now centers on cost and access. In the United States, where lemborexant has been available since 2019, monthly treatment runs approximately $300—roughly 1,600 Brazilian reais at current exchange rates. Brazil's drug pricing board, the Câmara de Regulação do Mercado de Medicamentos (CMED), will determine the local price. That decision will shape whether this new option becomes available to patients who need it most.
Dalva Poyares, a neurologist at the Brazilian Sleep Academy and professor at Unifesp, emphasizes that cognitive-behavioral therapy remains the gold standard for treating insomnia. Severe cases do require medication, often as part of broader treatment for other conditions—chronic pain, depression, cancer—that themselves disrupt sleep. When medications are necessary, doctors aim for the lowest effective dose, and when possible, they seek to discontinue treatment rather than maintain it indefinitely. The arrival of lemborexant gives clinicians another tool, particularly valuable for patients who cannot tolerate existing options or who need longer-term treatment without the dependence risks that have plagued earlier generations of sleep drugs.
Citas Notables
This medication blocks the action of orexin, preventing the signal that keeps a person awake— Lucio Huebra, neurologist and member of the Brazilian Sleep Academy
Severe cases require medication, often as part of treatment for other conditions like chronic pain, depression, or cancer— Dalva Poyares, neurologist at the Brazilian Sleep Academy and Unifesp professor
La Conversación del Hearth Otra perspectiva de la historia
Why does the mechanism matter so much? Isn't sleep just sleep, regardless of how you get there?
Because the brain doesn't forget how it got there. Z-drugs force sleep by dampening the entire nervous system—they're blunt instruments. Your brain adapts, demands more of the drug, and then struggles without it. Lemborexant is more like removing a brake than pressing an accelerator. The difference compounds over months and years.
The Oxford study ranked it highly but flagged inconclusive safety data. That's a contradiction, isn't it?
Not quite. The study looked at short and medium-term outcomes—where lemborexant excelled. But we don't have decades of real-world use yet. Anvisa approved it anyway, which suggests they weighed the known risks of existing drugs against the unknown risks of a new one and chose the bet on the new.
Seventy-two percent of Brazilians have sleep problems. That's staggering.
It is. But that number includes everything from occasional restlessness to chronic insomnia. Still, even if you narrow it to the 15 percent with chronic insomnia, you're talking about millions of people whose daily functioning is compromised. They're not sleeping well, and the drugs available to them carry real risks of dependence.
What happens when the pricing board sets the price? Will this drug actually reach people who need it?
That's the real test. At $300 a month in the US, it's expensive. Brazil will likely price it lower, but whether it's affordable enough to compete with generic Z-drugs that cost a fraction as much—that's the question that determines whether this approval matters in practice.
So cognitive-behavioral therapy is still the first choice?
Always. It works, it has no dependence risk, and it teaches you to sleep without medication. The problem is access and time. Therapy takes weeks. When someone is desperate and exhausted, they want a pill now. Lemborexant might be that pill for people who've failed therapy or can't access it.