Weight-Loss Drugs Don’t Appear to Work Against Alzheimer’s

GLP-1 drugs like Wegovy and Zepbound have been racking up sales and new indications, as researchers learn more about how the drugs affect the body beyond just weight loss.

But one of the more anticipated studies exploring how they impact Alzheimer’s disease has found no meaningful effect, Novo Nordisk said in a press release on Nov. 24

The company, which makes semaglutide (sold as Wegovy for weight loss and Ozempic for diabetes), said that its drug did not provide any additional benefit over placebo in two trials of people with early Alzheimer’s. The company released more data at a presentation at the Clinical Trials on Alzheimer’s Disease conference in early December and plans to share additional analysis at the Alzheimer’s and Parkinson’s Diseases conferences in March 2026.

"Of course it's disappointing; it's not the result we had hoped for or expected," Dr. Peter Johannsen, international medical vice president for Novo Nordisk, tells TIME. "We had expected to see something."

The two-year study included more than 3,800 people with mild cognitive impairment or mild dementia due to Alzheimer’s, half of whom were randomly assigned to take a semaglutide pill every day, and half of whom took placebo. The company said that people receiving the drug did show improvements in certain biological measures of Alzheimer’s disease, but that these changes did not translate into slower disease progression as measured by a standard test of several areas of cognitive ability, including memory, problem solving, sociability, and self-care. Experts are waiting for more detailed data on the results to understand whether the improvements in markers of the disease could be early signs of potential benefit, especially if combined with other strategies like behavior changes and currently available medications.

Read More: The Heavy Cost of Using Weight-Loss Drugs to Get Skinny

Johannsen, who presented the results at the Clinical Trials on Alzheimer’s Disease conference, said that those changes are encouraging signs that semaglutide "seems to do something" in Alzheimer's patients, even if the effects were not sufficient to translate into meaningful clinical changes in people's cognitive functions. Still, Novo Nordisk's CEO Maziar Mike Doustdar says the changes are worth exploring further to see if they translate into benefits for patients if combined with other treatments.

"I think the way we approach this is to not give up immediately, and to look at the data more and more," he tells TIME. "This is not the place to give up hope."

He says that semaglutide has surprised scientists when it comes to understanding how it works in the body, and that researchers are only beginning to uncover what those effects might be. "We have historically made no secret that that there are many things semaglutide does that, in our humble opinion, are probably connected to the secret sauce of the molecule that we don't fully understand. We will put our resources behind seeing where it takes us."

Researchers were hopeful that the weight-loss drugs might have an impact on Alzheimer’s, since inflammation contributes to the neurodegenerative disease and the drugs seem to have an anti-inflammatory effect. Studies in animal models, as well as observational studies of people taking the drug to treat diabetes or weight gain, hinted that the drug may slow the advance of Alzheimer’s.

New Alzheimer’s treatments are needed, since currently only two—lecanemab (from Eisai) and donanemab (from Lilly)—address the root causes of Alzheimer’s. Both work by attacking the buildup of amyloid plaques in the brain and can slow disease progression by up to 30% for people with mild-to-moderate disease. “These results will help us refine our understanding of this class of drugs,” said Maria Carrillo, chief science officer and medical affairs lead for the Alzheimer’s Association, in a statement. “Though this semaglutide pill did not help against Alzheimer’s, the field will continue to investigate this class of drugs, as they may act differently.”

Eli Lilly, which makes the other drug in the class, tirzepatide, has not said whether it plans to study its product’s effect on Alzheimer’s.

Novo Nordisk said it would discontinue a planned one-year follow up of the people in the trials.