INS and endothelial dysfunction: Because the impact of longer duration of supplementing GlyNAC in OA was unknown, we conducted a 36‐week open‐label trial to test whether supplementing GlyNAC for 24‐weeks in OA could improve or correct age‐associated GSH deficiency, OxS, impaired MFO, inflammation, endothelial dysfunction, insulin resistance, muscle protein loss, and body composition, and whether this could impact cognitive function, gait speed, muscle strength, and exercise capacity.