One expert said the results were a “game changer” in the treatment of type 2 diabetes.
The pill, costing just £1.30 (R21) a day, is taken before breakfast to lower blood sugar levels and keep weight down.
However, the analysis of 10000 patients in 30 countries reveals the drug, called canagliflozin, also has a remarkable impact on cardiovascular problems and kidney disease.
As these problems are strongly linked to type 2 diabetes, the treatment could make a huge difference to patients with the condition.
The findings, presented at a conference in San Diego in the US, found that the pills cut the overall risk of cardiovascular disease, which includes heart attacks and strokes, by 14%.
The medicine, sold under the trade name Invokana, slashed the risk of needing hospital treatment for heart failure by a third.
Patients were also 40% less likely to suffer serious kidney decline, a major side effect of diabetes.
Professor Bruce Neal, of The George Institute for Global Health at Sydney University, Australia, said: “Coronary heart disease is the biggest killer by far for people with type 2 diabetes.
“Our findings suggest that not only does canagliflozin significantly reduce the risk of heart disease.
“It also significantly reduced blood pressure and led to weight loss.” - Daily Mail