Study summary

The diabetes drug exenatide did not slow Parkinson's

Exenatide trial · 194 people at six UK hospitals · Published 2025, The Lancet

What was tested

Exenatide, a weekly GLP-1 injection used for diabetes, against placebo for 96 weeks, to see whether it slows the disease.

What they found

• Movement scores off medication worsened by 5.7 points on exenatide and 4.5 on placebo, not a meaningful difference.
• The earlier, smaller trial that had looked promising did not hold up.
• The investigators concluded exenatide should not be recommended to slow Parkinson's.

What it means

Closed the longest-running attempt to repurpose a diabetes drug for Parkinson's.