What medicine is good a alternative to metformin. I have horrendous side affects: 1. Diarrhoea 2. Nausea 3. lack of appettite 4. fatigue (in bed afer 8:30pm) 5. gas and Bloatness. 6. Mouth ulcers. I have been on metformin for 6 weeks now. 500g slow release daily. Its not getting any easier infact might be worse. I heard Forxiga is a good alternative ? Paul.