I have been on a very low dose of metoprolol for 3 months and have developed trouble sleeping and weight gain. I, too, hope the side effects will go away eventually. I take it for a-fib and there are worse Drugs out there with even worse side effects, so I stick with this. Tried Losartan and also Amiodarone with much worse side effects. I would like to go back to the ancient drug, digoxin, which I took years ago when I had a-fib following valve surgery, but once you are on a betablocker, it is hard to get off.