15mg didn't work for me, either. It was awful. I have osteoporosis. With the terrible side effects of Prednisone, I already felt that I'd made a deal with the Devil... only he didn't follow through with his side of the bargain. It was agonizing to put my elbows up and back, which is something you do a LOT (while getting dressed, for instance) - near-impossible, felt as though my arms were being forced against the way they were built. A week later the doctor bumped me up to 25mg. Pain was slightly less the next day, but it still took a few days before there was real effect. So much for the stories of instant relief.