I've been on Byetta for almost a year,and have had several dose changes. Initially, and with each dose change, I experienced about 2 days of nausea. It subsided for me. The nausea contributes to appetite suppression, but really, it slows aborption of food into the lower intestine, creating a feeling of satiety, and THAT is how it actually works to curb appetite.
I have to say that even though it still works well to control my blood sugar ( I take 3 injections a day: 2 from the 10 pen and 1 from the 5 pen), I have found that I seem to have developed a "tolerance",in that I no longer feel full or have appetite suppression while taking it. IN fact, the 8 pounds I initially lost, I regained.
Since Byetta was my last hope, and isn't working (for weight loss), I am getting banded!