New study to identify people likely to benefit from GLP-1 treatment for Parkinson's

A group of diabetes medications, called GLP-1 inhibitors, have long been explored as a potential treatment for Parkinson's, but results have always been inconsistent.

Read more about diabetes medications and Parkinson's on our research blog.

New research has highlighted that these inconsistent results may be because GLP-1 inhibitors, which are also used to treat obesity, work more effectively in some people with Parkinson's than others.

Now, Dr Cynthia Sandor, a researcher at Imperial College London and Group Leader at the UK Dementia Research Institute, is leading a new study, called STRAT-GLP1, to further understand who with Parkinson's is most likely to benefit from GLP-1 inhibitors, and whether they can be identified before treatment begins.

Who may benefit most from GLP-1 inhibitors?

In Parkinson's, brain cells which produce dopamine become damaged over time. As these brain cells are lost, dopamine levels in the brain get lower and lower. It's this lack of dopamine which causes symptoms of Parkinson's, such as stiffness and tremor, to develop.

Dr Sandor and colleagues at Cardiff University found, by studying information from Parkinson's UK funded research projects, that some brain cells which produce dopamine are more vulnerable to damage than others. The more vulnerable cells appeared to be resistant to insulin, which diabetes medications like GLP-1 inhibitors are designed to correct.

Researchers now want to explore whether people with Parkinson's with these insulin-resistant brain cells may respond better to GLP-1 inhibitors than those without these more vulnerable cells.

What will the researchers do?

In order to test GLP-1 inhibitors in the right people with Parkinson's, researchers must be able to identify who has these vulnerable brain cells.

STRAT-GLP1, which is funded by The Michael J. Fox Foundation, aims to develop a tool which can select people most likely to respond to GLP-1 medication. The tool will use several basic measurements, including blood sugar levels, cholesterol and blood pressure. It will also look for a number of different proteins in the blood which we know are linked to certain types of Parkinson's.

Who could benefit from the tool?

The STRAT-GLP1 study aims to develop a tool that as many people with Parkinson's as possible can access. The tool uses measurements typically taken in routine check ups, and aims to be cost-effective and widely accessible.

The study will also use genetic information from an American database called All of Us, where half of the participants are from underrepresented groups, including African and Hispanic/Latino groups. Combined with exploring whether men and women respond differently to GLP-1 treatments, the study aims to create a tool that's inclusive and relevant for many people living with Parkinson's.

Dr Cynthia Sandor shared: "If successful, this would be the first precision tool for GLP-1 therapy selection in Parkinson's, and it's designed from the outset to be clinically usable rather than confined to specialist research centres."

What does this mean for people with Parkinson's?

GLP-1 treatments have previously shown no significant benefits to people with Parkinson's in phase 3 trials. In 2025, a phase 3 trial of exenatide showed no benefits over the placebo, despite more positive earlier trials. Researchers now believe it's possible that many trials fail because we've not identified the right people to take part.

The STRAT-GLP1 study could change how we conduct clinical trials of new drugs for Parkinson's by involving people who are most likely to benefit. This has the potential to speed up the search for new drugs, and get better treatments into the hands of people with Parkinson's sooner.

Emma Rodgers, Research Communications Manager at Parkinson's UK shared:

"Parkinson's is a complex condition. We desperately need new drugs to help slow and stop it from progressing, and it may be that a more personalised approach will help us get there sooner.

"Conducting clinical trials with people who have been identified as likely to benefit may help us find the right drugs for the right people. We're encouraged to see the STRAT-GLP1 study explore this for GLP-1 inhibitors, and pleased to see accessibility and inclusivity at the forefront of the trial."