adding cereal to formula

So my son is a little over a month old, and has been having problems staying asleep (yes I know he's still young but this is all of a sudden, he usually sleeps long stretches especially at night). I talked to my mom and his fathers mom and they both said they added a little cereal to bottles to help baby sleep. Fathers mom said she added it as soon as 3 weeks, my mom in the other hand didn't start adding til we were like 2 months. Any suggestions??