The progression of chronic kidney disease is difficult to stop once established. Metformin and sodium-glucose cotransporter 2 inhibitors show promise, but clinical trials with a head-to-head comparison in patients with more advanced (stage 3b-4) chronic kidney disease are largely lacking, partly for safety reasons. In this issue, Corremans et al. compare the effects of metformin and canagliflozin in rats with adenine-induced moderate (stage 2-4) chronic kidney disease. Metformin halted progression, whereas canagliflozin did not. This commentary puts the results in a wider clinical context.