Januvia
"I have had no side effects from Januvia.  My A1C went from 9.2 to 5.5 using 1500 mg of Metformin and 100 mg Januvia, and adjusting my diet and exercising a bit.   I am lucky in tht neither Metformin or Januvia seems to bother me.

There is a savings certificate on the Januvia site to keep the co pay down to $5, normally it would be $55 for me."