I take 2 500mgs tablets before bed and by the time I wake up about 8 hours later I pretty much have to boot it to the bathroom. I decided to take my metformin at night because I figure I'd be able to sleep off any upset stomach issues so I take it right before I climb into bed. So far so good, and once I have my initial "bathroom run" in the morning, I'm ok for the rest of the day (actually, I feel great for the rest of the day given the fact that it pretty much cleans my system out).

It really does depends on how well YOUR body tolerates it though. Some people won't have any side effects from it (my dad, for example, is on 2500mgs/day for T2 diabetes and has had NO reaction whatsoever), and some will feel sick soon after.

What i found helpful was to start taking it on a weekend so I didn't have to deal with possible side effects during the week when I had to work. I have a few other medications I take as well and I find introducing new meds when I have a couple days off helps a lot.

And remember, it's common for initial metformin side effects to subside within a couple weeks or so.