And to back up the OP here in terms of the blood work, since both blood tests for IGF-1 are within the normal range for the reference ranges...even though the testing center and the reference ranges are different, they are actually at worst showing a decrease and at best showing no change at all. Since they are different ranges, but both are within the range and somewhat midline, I would conclude that, just like his friends reported levels, his show that there was actually NO CHANGE. I would not conclude that there was a decrease like some have said. I would argue the best conclusion is to say that they are both equivalent (especially once you factor in variability in levels from normal day to day changes).