MSG does not act on your brain first, it hits your tastebuds first then signals to your brain that it enhances flavours MSG is simply a sort of amino acid found in tomatoes, mushrooms, and cheese. It’s meant to bring out the umami in foods and technically can be put on a wide variety of things like ice cream. MSG doesn’t increase appetite hormones, but it makes food incredibly palatable to the point where you want to eat more of it. No, it’s not bad for you. There’s no consistent evidence to say that it’s bad, but all things in excess is bad for you.