Shrubby Sophora (Sophora flavescens), known as "Ku Shen" in traditional Chinese medicine (TCM), has a long history of use in East Asia for managing inflammatory conditions, including symptoms similar to those found in rheumatoid arthritis (RA). Traditional usage is largely based on its purported anti-inflammatory, analgesic, and immune-modulating properties. In TCM, it is used to "clear heat" and "eliminate dampness," concepts that are sometimes associated with inflammatory and rheumatic diseases.

Modern scientific research on Shrubby Sophora for RA specifically is limited. Some laboratory and animal studies have explored the plant’s active compounds, such as matrine and oxymatrine, which have demonstrated anti-inflammatory and immunosuppressive effects. However, robust clinical evidence in humans with RA is lacking. There are a few preliminary studies and case reports suggesting potential benefit, but these are not sufficient to establish efficacy by modern scientific standards.

Therefore, while the use of Shrubby Sophora for RA is primarily justified by tradition, and there is some low-level scientific rationale based on its pharmacological properties, high-quality clinical trials are lacking. The evidence supporting its use for RA is modest (rated 2/5), reflecting traditional use with limited scientific validation.