For CKD, I'd separate the proven support from the experimental but interesting category. Astragalus root extract is probably the most tried and true natural compound I'd look at first. There's actual human data showing Frontiers Nano Technological Approaches for Targeting Kidney Diseases With Focus on Diabetic Nephropathy: Recent Progress, and Future Perspectives Uremic Toxin an overview ScienceDirect Topics Glutathione Injection Phoenix: A Health Revolution