lemborexant already on pharmacy shelves just showed promise in fighting Alzheimer’s-related brain loss

A pill already on pharmacy shelves just showed promise in fighting Alzheimer’s-related brain loss.

The drug, known as lemborexant, is already prescribed for insomnia and works by blocking orexin, a brain chemical that regulates sleep.

In a study led by researchers at Washington University, mice that took lemborexant had up to 40% more preserved brain volume in the hippocampus—the area involved in memory—compared to mice that took another sleep drug, zolpidem, or no drug at all.

This brain protection was linked to a significant reduction in tau protein buildup, which is one of the key factors behind cell damage and memory loss in Alzheimer’s disease.

What stood out is that these effects weren’t simply due to better sleep.

Both lemborexant and zolpidem improved sleep, but only lemborexant slowed tau buildup. This suggests the specific way lemborexant promotes sleep—by targeting orexin—may directly affect brain health.

However, the results only appeared in male mice, and researchers aren’t sure why females didn’t show the same benefit. It’s also unclear if the same protective effect will happen in humans, especially since lemborexant is currently approved only for short-term use.

More research is needed, but the findings suggest that drugs like lemborexant, if given early, could one day help delay or slow the progress of neurodegenerative diseases like Alzheimer’s.