Weight Loss Drug Semaglutide Shows Promise as Alzheimer's Treatment

Scientists are trying to tackle Alzheimer's from all angles, and a new study adds to the growing evidence that semaglutide, a widely used diabetes and weight loss drug, could also be beneficial in easing some of the disease's symptoms.

Researchers in China used mouse models of Alzheimer's disease to investigate the effects of the drug, sold under brand names such as Ozempic for type 2 diabetes and Wegovy for weight loss.

Semaglutide appears to help immune cells switch to a more protective state, suggesting its potential to slow or prevent disease progression.

In Alzheimer's mice (known as 3xTg), treatment with semaglutide over the course of a month showed numerous positive signs compared to placebo. In the brains of 3xTg mice, for example, the drug reduced the levels of amyloid-beta protein build up, a toxic process that comes in tandem with Alzheimer's.

Then in experiments set up to test memory and learning, 3xTg mice treated with semaglutide showed improved long-term and short-term memory performance – almost on a par with the healthy mice being used as a control.

"These behavioral results showed that exogenous administration of semaglutide significantly improved the learning, memory, and cognitive behavior disorders of 3xTg mice," write the researchers in their published paper.

There were more benefits too. The treated mice showed reduced levels of molecules known to trigger inflammation in the brain, while boosting the number of molecules with anti-inflammatory properties.

And that's crucial to the effects of semaglutide, the researchers think: a reduction in the damage inflammation does to brains with Alzheimer's. This inflammation is partly down to immune cells called microglia.

In the brains of the treated mice, some microglia switched from attack (a mode known as M1) to a more neutral state (M2).

This switching of microglia activity was also shown in further lab tests carried out by the researchers: semaglutide was shown to change the response of immune cells to the presence of amyloid-beta proteins.

"We speculate that semaglutide shows an anti-inflammatory effect by promoting the transformation of microglia from M1 to M2 type in the brain of 3xTg mice, and thus exerts a neuroprotective effect," write the researchers.

The link between semaglutide and protection against Alzheimer's has been made before. Scientists are still trying to figure out the extent of this protection and the mechanisms responsible for it, so that effective treatments can be developed.

Semaglutide could well be effective in reducing the damage done by Alzheimer's, based on these results – or perhaps stop it from fully developing in the first place.

While these results in mice need to be replicated in people, and over a longer term, efforts to get those confirmations have already begun. That means new hope for the millions of people living with Alzheimer's – and the millions more at risk of it.

"Previous studies have shown that semaglutide is effective in Parkinson's disease and stroke," write the researchers. "Importantly, Phase 3 trials of semaglutide in Alzheimer's disease patients are currently underway."

The research has been published in Neuroscience.