Metformin doesn’t cure diabetes instead, it helps to lower your blood sugar level into safe level.Metformin needs to be taken for long term. This may make you wonder what side effects can cause.If Metformin kills then why it is used? Answer is simple most of the doctors are least bothered about your life. They only think about their earnings.If you are having a heart problem you should not take Metformin your heart may not send enough blood to your kidneys. This would prevent your kidneys from removing Metformin from your body as well as they normally would.raising your risk of lactic acidiosis.