is it bad that my 5 month old drank formula that was not good nomore?

What do you mean when you say it wasn't good? Was it a few hours old? If it was truly funky, your baby wouldn't drink it. Babies don't eat or drink stuff that is truly gross. (My baby has only had breastmilk and won't drink formula and barely tolerates juice.) Formula doesn't really go bad as quickly as everyone says it does. My older two kids were formula babies and sometimes bottles would sit around for a while. As long as they didn't smell bad (other than the normal formula smell, which is, in itself, a little gross), it was fine. They never got sick.Depending on how old/bad it was, it could make her a little sick. Just watch her behavior. If she starts throwing up, you'll know it was really bad. But chances are, she'll be just fine.