I hope it doesn't change its colour or give kidney problems because I'm newly diagnosed as type 2 diabetes . It was a blood pressurectablet that gave me the diabetes and the diavetes nurse put me on metformin, so I can do without all medicines doing me harm instead of good .it angers me to know that pharmesudical companies can be letting drugs out that dont help the patient . I must admit the nurse warned I may get tummy ache when I first started taking netformin and I did. I've also just had infection and couldn't control it but just finished antibiotics. The last few days I've noticed very dark yellow urine but I'm always drinking water/tea/coffee . I also have osteoarthritis of the knee and have been immobile for the past year so suddenly having urine problems is very embarrassing