Testosterone replacement therapy and kidney health are more closely linked than most men realize. Chronic kidney disease (CKD) commonly causes low testosterone, and in men with hypogonadism, TRT has been shown in several studies to preserve or even improve kidney function rather than harm it. The bigger concern for men with existing kidney disease is not the kidneys directly, but how TRT's effects on fluid balance, blood pressure, and red blood cell count interact with a kidney that is already under strain.
Why Does Kidney Disease Cause Low Testosterone?
CKD disrupts the hypothalamic-pituitary-gonadal axis, the hormonal signaling chain that tells the testes to produce testosterone. The uremic environment created by declining kidney function interferes with that signaling directly, and the chronic inflammation and nutritional deficiencies common in CKD suppress gonadal function further (Zitzmann, Journal of Clinical & Translational Endocrinology, 2024).
This is not a rare overlap. Testosterone deficiency affects an estimated 30 to 70 percent of men with CKD, depending on disease stage and which diagnostic threshold is used, and low testosterone in this population is associated with worse muscle wasting, lower quality of life, and higher cardiovascular risk (La Vignera & Condorelli, European Journal of Internal Medicine, 2026). Kidney disease itself is common in the United States, affecting more than 1 in 7 adults, or an estimated 35.5 million people (NIDDK), so the overlap between the two conditions touches a meaningful share of men considering TRT.
Can TRT Improve Kidney Function in Hypogonadal Men?
The research points in a more encouraging direction than many men expect. An eight-year observational cohort study followed 496 hypogonadal men, 312 of whom received long-term testosterone undecanoate and 184 of whom did not. The treated group's estimated glomerular filtration rate (GFR), the standard measure of kidney function, rose from an average of 87.0 to 98.0 mL/min/1.73m2 over the study period, while the untreated group's GFR declined from 92.0 to 87.0 over the same span (Alwani et al., Annals of Medicine and Surgery, 2021). The treated group also had a lower overall death rate (7.8 percent versus 15.2 percent), and cardiovascular causes accounted for a smaller share of those deaths.
More recent review data reinforces this pattern. Emerging observational studies show CKD patients treated with TRT tend to have preserved or improved GFR compared with untreated controls, alongside measurable gains in hematologic parameters, nutritional markers, muscle strength, and quality of life (La Vignera & Condorelli, European Journal of Internal Medicine, 2026). None of this proves TRT reverses kidney disease, but it does undercut the assumption that testosterone therapy is inherently risky for the kidneys.
What Are the Risks of TRT for Men With Kidney Disease?
The risks that matter most for CKD patients are less about the kidneys themselves and more about how TRT's known side effects interact with a compromised system. Testosterone therapy can cause fluid retention and raise blood pressure in some men, effects that carry more weight in someone whose kidneys are already less able to manage fluid and sodium balance, and clinicians are cautioned to watch for exacerbation of existing heart failure in this population (Zitzmann, Journal of Clinical & Translational Endocrinology, 2024). If you want the fuller picture on how TRT affects blood pressure specifically, see our guide to TRT and blood pressure.
The other major consideration is erythrocytosis, the excess red blood cell production TRT can trigger. CKD patients are more likely to already be managing anemia, which complicates the picture, but a rapid or excessive rise in hematocrit still carries the same clot risk it does in any man on TRT. Large trial data show TRT is generally noninferior to placebo for major adverse cardiac events, but researchers flag ongoing vigilance for atrial fibrillation and acute kidney injury as open questions worth monitoring closely in this population (La Vignera & Condorelli, European Journal of Internal Medicine, 2026). Our guide to TRT and hematocrit covers how that risk is tracked and managed in more detail.
Does the Delivery Method Matter for Kidney Patients?
Yes, and this is one of the more practical takeaways from recent research. Transdermal testosterone gels produce steadier, more physiological testosterone levels than intramuscular injections, without the sharp peaks that injections create. That steadier profile translates into a meaningfully lower risk of excessive erythrocytosis, which matters more in CKD patients who may already have less reserve to tolerate thicker blood (La Vignera & Condorelli, European Journal of Internal Medicine, 2026). For men with kidney disease, this is a reasonable factor to raise with a prescriber when choosing between formulations, alongside cost and convenience.
What About Men on Dialysis?
Testosterone deficiency is especially common in men on hemodialysis, and the anemia that comes with advanced kidney disease is one of the areas where TRT's effect on red blood cell production can work in a patient's favor rather than against it. Because testosterone stimulates erythropoiesis, some dialysis patients on TRT see improvement in anemia-related fatigue alongside gains in muscle strength and reported quality of life (La Vignera & Condorelli, European Journal of Internal Medicine, 2026). That said, dialysis patients need tighter monitoring than the general TRT population, and treatment decisions in this group should be made jointly by a nephrologist and the prescriber managing testosterone therapy, not by either specialist alone.
