Re: I took lots of creatine 3 years ago.
I've wondered the same thing...I used to take a lot of creatine, and it would make me feel kind of nauseous, but I figured that was normal...I have had all kinds of minor health issues since then, seemingly most closely related to liver and/or kidneys (thin/brittle hair, poor digestion, ridged fingernails, etc.)
If you figure anything out, let us know. I'll try and do the same. I plan to speak to a naturpathic doc I respect a lot about supplements/strategies for strengthening the liver/kidneys.
FYI, I have heard that the liver can rejuvenate itself rather quickly (4 months?), but it takes much longer for the kidneys to heal. My theory is that if there is a lot of damaged tissue, it will take a very long time to restore the the kidneys or the liver, though, as your body will rejuvenate new liver cells, but the new cells will replicate what is already there...my theory can be compared to a scar from a scrape on your knee.
As a kid, I used to ride my bike, crash, slide, etc., and scrape my knees up a lot. The skin on my knees was scarred for several years, though the skin goes through a complete shed much more often than that. But, eventually, years later, I don't have those scars on my knees anymore.
Hopefully, this will work for a damaged liver / kidneys as well.