I'm probably a little late in replying to you, but maybe can help anyone else who comes along.
I'm currently 34 (35 in 2 months) and have been on both prednisone and mycophenolate (cellcept) since I was 21. Well, I was on Prednisone almost non-stop up until I was about 32 with doses as high as 120mg/day, but the last several years doses were typically between 10-60mg depending on if I was in remission or not. I have been on 3g (1.5 2x daily) of mycophenolate for the last several years and finally was reduced to 1.25g 2x daily about 6 months ago.
Comparatively, mycophenolate is like a vacation in the Bahama's while prednisone was like a sentence on the rock (presumably). Since I haven't actually not been on medication for over 13 years, and at the time being 21 I was very healthy, extremely in shape and generally very happy with life, I think it would be near impossible for me to compare it to what I would 'normally' have been at ~35 w/o medication. But I will say that in general being on mycophenolate has been relatively easy.
Some things I will comment on are though, I definitely have GI issues; however, I remember also having them semi-frequently though my teens too. I also have issues sleeping, which I've also had for years prior to starting medication, which I'm sure it's not helping anything. I also have a loss of motivation and general loss of energy, but having gained a significant amount of weight while on Prednisone, and a recent back injury thats restricted my exercise for the past 3 years I feel are major contributors. Like I said, I was very in shape at 21, so much of my comparisons are to my 21yr old self.
But back on topic. My wife and I had been trying to conceive for the past year or so. After no luck, I went to see a specialist and found out I've got a severely low sperm count. This was based off a single sample though, with no other tests or diagnosis done. I've setup more tests over the next month to determine potential issues with my testes (infections, etc.) due to prolonged use of immunosuppressants, genetic defects, lowered hormone levels, etc. My Dr. also told me he's never heard that prednisone has any issues with lowered sperm count.View Thread