I have a big can of formula, and only use it once in a while when were out of the house and to mix with cereal. i usually bf. but its been over a month now, so im not sure if i should toss it or use it. because they cost so much, i dont want to let it go to waste. what do you all do???

You are supposed to throw it out after a month. You would probably be okay stretching that a little, like a week maybe, but I wouldn't use it after that.

liquid is only good for 48 hours and powder a month. i would not take any chances.