The study may suggest that other researchers should be less optimistic about the prospects for treating a range of other conditions with newer weight-loss drugs.

The GLP-1 drug, exenatide, has no positive impact on the movement, symptoms or brain imaging of people with Parkinson's, finds a new study led by UCL researchers.

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.