What is the longest amount of time it takes to go away? I took prednisone starting in September of this year and was off of it completely in the end of October or beginning of November and my moon face was reeeeally bad, but it's not bad anymore. BUT, when I look at pictures from before taking it, my face is not as slim as it was before? Is it still in my system? Or what because I still don't look the same.