Hi, I'm 52 years old and live in New Hampshire. I was diagnosed with type 2 diabetes in early 2016. I currently take Metformin XR. Last year in July I was diagnosed with a cholesterol granuloma benign cyst in my skull near my temporal lobe that required surgery. While I was in the hospital they put me on insulin instead of my metformin. I had been working very hard to try to get my bg under control, but it's been a nightmare since my surgery. I've been having some complications and was just released from being an inpatient with a suspected CSF leak. They couldn't find anything emergent, so they sent me home to monitor my symptoms. They had me on insulin again in the hospital and now I'm back on my metformin, but my bg readings are still all over the place. My PCP has been made aware of these crazy bg numbers and said things should stabilize. My question is how long does it take for my metformin to start working again? This may be the wrong place to ask this, but it's part of my introduction.