I can understand your concern.
The yellow urine indicates a lot of things like even if you are not taking enough water, the urine can be yellow.
As said by my colleague, if you are on any multivitamin also it can be yellow. Have you started noticing after taking the glyciphage tablet or was OK in the past with the tablet also?
Urinary tract infection can also cause a dark coloured urine.
Here is what you can do, drink upto four litres of water a day and get a urine complete test done.
Consult a physician in case it doesn't get solved by taking lots of fluids.
Dr. Anil Kumar Jain.