I had fasting blood sugar level of 268 a month back. After regular exercise and strict diet, in a months time, i brought the fbs level to 150 from 268. But still, as the reading of 150 is high, I consulted a diabetician and he prescribed Instamet 50mg/500mg along with thyronorm(for sub-clinical hypothyroidism). Is Instamet 50mg/500mg free from side effects, as the doctor said ?