Chinese Thoroughwax (Bupleurum chinense), known as Chai Hu in Traditional Chinese Medicine (TCM), has a long history of use in herbal formulations, particularly for harmonizing and supporting liver function, alleviating fever, and addressing stress-related symptoms. In TCM, the concept of "supporting the adrenal cortex" does not directly exist, but Bupleurum is traditionally used in formulas (such as Xiao Yao San) to help the body adapt to stress and maintain balance, which some modern practitioners analogize to "adrenal support." The historical use is grounded primarily in TCM theory rather than direct evidence of action on the adrenal glands themselves.

Scientific research on Bupleurum focuses mainly on its anti-inflammatory, hepatoprotective, and immunomodulatory effects. There is limited preclinical evidence suggesting Bupleurum extracts may influence the hypothalamic-pituitary-adrenal (HPA) axis, which is involved in the body’s stress response. However, robust clinical trials demonstrating a direct benefit to adrenal cortex function in humans are lacking. Thus, while the traditional use is well established, the scientific validation for direct adrenal cortex support is limited and mostly inferential.

In summary, the use of Chinese Thoroughwax for supporting the adrenal cortex is primarily justified by traditional practice, with only preliminary and indirect scientific support.