I also developed a very ugly moonphase with prednisone. It was so bad that when I toured Namibia the officials at the airport thought that the photo on my passport was that of another person. (The photo was taken before I went on prednisone).
My moonphase disappeared when I started having cinnamon tea 3 times a day. Place about 2 cinnamon sticks in a small kettle and boil and simmer. Cinnamon has it's own sweetness so no need for sugar. You should see a difference in about 2 weeks