Phragmites australis, commonly known as common reed, has a long history of use in traditional Chinese medicine (TCM) and other herbal traditions. In TCM, the rhizome of Phragmites (known as "Lu Gen") is often used for its purported cooling and detoxifying properties. It is believed to clear heat, promote urination, and support the body's fluids, which includes applications in certain kidney-related conditions such as urinary tract infections, edema, and difficulties with urination. These traditional uses are documented in classical TCM materia medica texts and are still referenced in modern herbal compendia.

However, there is limited scientific research directly validating the efficacy of Phragmites for supporting kidney function specifically. Some preliminary studies suggest anti-inflammatory and diuretic effects, but robust clinical trials demonstrating clear benefits for kidney health in humans are lacking. Most of the support for its use in the kidney system comes from longstanding tradition rather than modern experimental or clinical evidence. As such, while it remains a part of traditional herbal practice, the evidence base according to modern scientific standards is currently weak.