Placebo used in this trial is a foodgrade clinical trials

Treatment of vascular stiffness in patients with autosomal dominant polycystic kidney disease

This study is looking at ways to improve blood vessel health in people with Polycystic Kidney Disease (ADPKD). It compares a high-salt diet to a potato starch placebo and tests a common medication called amiloride to see how it affects blood vessel stiffness.