I am Type 2 diabetic and have been on Metformin ER for a few years. My thyroid tests have always been normal. Three months ago I was put on Janumet (combination Januvia and Metformin). I just went for bloodwork and for the first time ever my TSH is elevated (5.04) and my T4 Free is low (.8). Does anyone know if the Januvia is responsible for these changes? It seems more than a coincidence. My next appointment with my endocrinologist is in 3 months and I will repeat these tests again.