on or off cycle, kidney heath is very important. high protein diets can be a strain so no matter if you're using gear or not, the only way you can know for sure how your organs are doing, is go in and get blood work done. for a natural athlete, i think that every 6 months is an ok time frame, but for those of us using gear, it is imperative to get labs done more often. i usually go in every 3 months. if i am at all concerned about organ health, i will have labs run at that time. if you don't have a Dr you trust, there are online companies that you can order your labs through, then you just go down to a place that will draw your blood. they will let you know of places in your area and you're all set. ideally, you have a dr that will understanding of your needs and is willing to work with you. if you don't you should find a new Dr.
there are a couple of things that you can do to help your kidney function out. first of all, make sure you are constantly flushing them with water. some people can drink more than others. personally, i consider myself at the low acceptable end, drinking about 1 to 1.5 gallons a day. you want your urine to be light in color. never dark yellow and never with an oder. if you notice either of these things, the first change i would make is to up your water. also, make sure that your blood pressure is in check. high BP will put a strain on your kidney function over time. this is a major cause for kidney damage in our sport. sadly, too many guys ignored the signs for a long time and suffered in the long run because of it. renal failure isnt something that will happen over night. it's something that might show up several years later. take care of yourself now, so that you will have your health for the rest of your life