Paeonia moutan (also known as Moutan Cortex or tree peony root bark) is primarily used in Traditional Chinese Medicine (TCM) and other East Asian herbal traditions. Its use for edema is based on its traditional classification as a blood-cooling and blood-moving herb, often included in formulas intended to address "stagnation" and "dampness"—concepts in TCM sometimes associated with fluid accumulation like edema. Historical texts, such as the Shennong Bencao Jing and subsequent materia medica, mention Paeonia moutan for conditions involving swelling, inflammation, and fluid retention.

However, scientific evidence supporting its use specifically for edema is limited. Some pharmacological studies have identified anti-inflammatory and antioxidant properties in extracts of Paeonia moutan, and these may provide a plausible mechanism for reducing certain types of swelling. Yet, rigorous clinical trials or animal studies focusing directly on edema are lacking. The traditional use is typically as part of multi-herb formulas, making it difficult to attribute any effect solely to Paeonia moutan. In summary, while there is a long-standing tradition of using Paeonia moutan for symptoms related to edema, scientific validation for this specific indication remains minimal.