Is 120 mg of xanax dangerous?

Yes it can, considering the standard dosages are from between .25 and 2.0 mg. You could either die from the actual overdose, or you could find yourself choking to death trying to swallow 115 pills (and thats assuming your taking the 2mg pills). If your stuck with the really weak ones (.25mg), you could find yourself trying to choke down 920 pills!!