Sodium-glucose co-transporter 2 (SGLT2) inhibitors lower blood glucose by reducing the reabsorption of glucose in the kidney. They are a second-line therapy for type 2 diabetes. During clinical trials it was noticed that SGLT2 inhibitors had favourable effects on cardiovascular and renal disease. This led to further trials that included patients without diabetes. In studies of heart failure, SGLT2 inhibitors were beneficial in treating patients with a reduced left ventricular ejection fraction. A recent study has also reported benefits in patients with a preserved ejection fraction. In chronic kidney disease, SGLT2 inhibitors may reduce disease progression. However, a decline in the glomerular filtration rate may be seen at the start of treatment. As most experience with SGLT2 inhibitors is in diabetes, patients without diabetes need to be aware of why they are being prescribed these drugs. Some of the potential indications for SGLT2 inhibitors beyond diabetes are not yet approved by regulatory authorities.