When is the best time to take metformin extended release 2000mg-am or pm? or 1000 in morning and 1000 at night?

It’s important to take the medicine exactly as your doctor directed because s/he is taking all of your medications and health history into account. In truth, there’s little difference between the two approaches. It’s possible that splitting the dose may lead to slightly better blood sugar control but at the risk of having to take more doses, increasing the risk of missing or forgetting some doses.