I've heard that it raises liver values, at least temporarily, so I agree with the above. I always take 1000mg of milk thistle year round anyway to help keep the liver healthy. I've also heard it debated that fina is tough on the kidneys too. I take cranberry during all cycles anyway, so whether it is or isn't, I'm not sure, but I take the precaution with the renal system supps anyway. I believe that if you have kidney issues with it, you're probably NOT drinking enough water. If you drink 1+ gal of water a day, I doubt you'll ever have issues.