Scrophularia root, known as "Xuan Shen" in Traditional Chinese Medicine (TCM), has a long history of use for treating various conditions related to the lymphatic system, particularly swollen lymph glands, sore throats, and nodular swellings. In TCM, it is classified as having "heat-clearing" and "detoxifying" properties, and is often employed in formulas aimed at resolving "toxic heat" and dissipating nodules, which are interpreted as swellings such as enlarged lymph nodes. Ancient Chinese medical texts, such as the Shennong Bencao Jing and later herbals, describe its use for "scrofula" (a term historically referring to tuberculous lymphadenitis) and other forms of glandular swelling.

While modern pharmacological studies have identified some anti-inflammatory, immunomodulatory, and antibacterial properties in Scrophularia root extracts, there is very limited direct clinical evidence supporting its effectiveness for swollen lymph glands specifically. Most of the scientific studies focus on in vitro or animal models, with few rigorous human trials. Therefore, the primary justification for its use in this context remains traditional, based on centuries of empirical use within TCM rather than contemporary biomedical research. The evidence rating reflects the strong historical precedent but the lack of robust clinical validation.