Yeah, I gained about 3 to 5 pounds the first week too. It came off within about 2 days once I upped my dosage to 1000mg. Unfortunately, I've barely been eating anything and yet, I'm not losing weight now.
I gained over 1.5 lbs in one week with 1000mg of XR but was fine with the regular Met. I've hardly been eating either and when I do it's low-carb, healthy, etc. I've also continued my exercise routine at least 3 times a week with a trainer--so I haven't been slacking it!
I initially lost 4 lbs the first week I was on Met but in the two weeks following I have gained that back. I've been on 1000 mg for almost two weeks. Not sure what is going on. I don't have an appetite and have to make myself eat and I'm following a low GI, low carb diet with excercise.