Hi Julia,
Well my experience was similar to yours. 5mg didn't really move my numbers much but when I went to 10 mg., wow...my numbers plumeted. I was able to half the doses of metformin and glipizide that I took daily and drop one of my medications alltogether. Not to be the harbinger of bad news but the 10mg traditionally has given most people (lizard bite) and made them extremely nauseous even if the 5 mg had no side effects. I was one of the lucky ones in that it never bothered me!
I have not really lost any weight on Byetta, but then again, I don't really have to lose any weight, so perhaps it is a moot point. Weight loss is a SIDE EFFECT and an acillary benefit. It certainly is NOT the primary reason or one of the reasons that Byetta is or should be prescribed!! If you are a type 2 and produce any insulin, Byetta will help preserve and even regenerate your beta cells while increasing your sensitivity to insulin. It is sometimes a monotherapy but I see it being prescribed mostly to people that are maxing out on oral meds (and that happens all to often). As an "incretin mimetic" there are several new drugs in its class that have come to market or will be here soon. So far Byetta seems to be the most effective but only time will tell!
Let me know when you move to the 10mg dose and maybe I can give you some help in getting by the nastiness of the side effects.
Warren