Eucommia ulmoides, commonly known as Du Zhong, has a long history of use in Traditional Chinese Medicine (TCM), primarily for supporting the Kidneys and Liver. In TCM theory, the Kidneys are believed to govern bone health, vitality, and reproductive functions. Eucommia ulmoides is frequently prescribed to "tonify Kidney yang," which is associated with boosting physical strength, supporting the lower back and knees, and improving reproductive health. Historical texts such as the "Shennong Bencao Jing" (Divine Farmer’s Classic of Materia Medica, Han dynasty) describe Eucommia as a remedy for Kidney deficiency syndromes, used over centuries in formulas for conditions like lower back pain, fatigue, and weakness.

While there is some emerging scientific research on Eucommia ulmoides, including its potential antihypertensive, anti-inflammatory, and bone-strengthening properties, these studies are generally preliminary and do not directly validate its use specifically for "Kidney support" as understood in TCM. Most evidence for its role in supporting the Kidneys remains based on traditional usage and clinical experience within the context of TCM, rather than on robust modern scientific trials. Therefore, its reputation for Kidney support is primarily justified by tradition, with moderate strength of historical evidence and only limited scientific exploration to date.