Blocking the mineralocorticoid receptor (MR) is one of the most effective ways of reducing blood pressure in patients with resistant hypertension and improving cardiovascular prognosis in patients with heart failure with reduced ejection fraction and left ventricular dysfunction after myocardial infarction. Blockade of the biological effects of aldosterone has mostly been achieved with spironolactone and eplerenone, the two steroidal MR antagonists currently on the market. Development of new non-steroidal dihydropyridine-based third- and fourth-generation MR antagonists is ongoing. These antagonists are highly selective for the MR, but have no effect on the glucocorticoid, androgen, progesterone and estrogen receptors, in contrast with spironolactone.