Hi . Most people take to Metformin. It may cause diarrhoea, upset stomach at first especially if taken on an empty stomach. The good news is these symptoms usually go away within a few weeks. If not? Then you should go and see your GP who can prescribe the Slow Release Metformin which is much kinder to your stomach. I have been on the SR Version and it gave me indigestion and terrible Abdominal pains, and so I was prescribed the Standard Metformin and I never had any problems - and 15 years later I am still taking the Standard Metformin without any problems.