My doctor has reduced my Metformin to one 500mg a day. Is it best to take this after my main meal of the day (usually lunch) and does it matter if this varies?
If that's the best time for you to take it then I think that would be fine - I wouldn't vary it though - try to take it at roughly the same time everyday
As long as you stick to the same time of day it will be fine. I work shifts so I always take mine at the same time (in the evening) whether I'm getting up or coming in from work works well for me as it's always 24 hrs apart.
It apparently builds up in your body - it is not something instant, so if you take it when it has least impact - if it does have consequences other than those desired - that should give you as much help as possible.
I use mine as laxatives - I've taken three this year, I think. So far I've been absolutely dandy.