• Posted February 5, 2025

Ozempic-Type Drug Fails To Slow Parkinson’s, Study Finds

Hopes that GLP-1 drugs such as Ozempic and Wegovy could help slow Parkinson's disease have taken an hit.

A new study found that a drug in the same class called exenatide, marketed as Byetta, had no effect on slowing the disease or easing its symtoms.

The trial, published Feb. 4 in The Lancet, followed 194 people with Parkinson's disease for 96 weeks. 

Patients were randomly assigned to inject either Byetta or a placebo once a week. The results? Disappointing.

"We found no evidence to support exenatide as a disease-modifying treatment for people with Parkinson's disease," researchers wrote. 

There was no improvement in symptoms; no slowing of brain degeneration; no benefit on brain scans; no positive effect.

“It’s hugely disappointing,” Dr. Thomas Foltynie of University College London, who led the trial, told The New York Times. “We were expecting we would come through and we would get a positive result.”

For years now, researchers have hoped that GLP-1 drugs, which have revolutionized treatment of diabetes and weight loss, could also protect neurons and slow brain disease.

In fact, early animal lab studies and smaller clinical trials suggested potential benefits, The Times reported.

But this larger study offered no clear evidence that GLP-1 drugs work for Parkinson's. 

“This is a sobering moment,” Dr. Michael S. Okun, a Parkinson’s disease expert at the University of Florida and national medical adviser for the Parkinson’s Foundation, told The Times. “This is a really well done study and it came up empty-handed.”

The study could also impact research into GLP-1 drugs for Alzheimer’s disease, as some researchers have been testing whether these medications might help slow cognitive decline. 

But Parkinson’s specialists warn that without a clear understanding of how GLP-1 drugs work in the brain, future studies may be just as disappointing.

“I wouldn’t do another study like this unless you learn what is the target,” Dr. David Standaert, a Parkinson’s researcher at the University of Alabama at Birmingham, told The Times. “What is the biochemistry you are trying to change in the brain? How do these drugs work, anyway?”

More information

The Parkinson's Foundation has more on the disease, causes, signs and more.

SOURCES: The New York Times, media report, Feb. 4, 2025; The Lancet, Feb. 4, 2025