Hu Zhang (虎杖), known botanically as Polygonum cuspidatum or Japanese knotweed, has a long history of use in Traditional Chinese Medicine (TCM). In TCM, it is believed to "clear heat," "remove toxins," and "invigorate blood." Its use for gallbladder issues is primarily rooted in its traditional functions, particularly for conditions described as “damp-heat,” which may correspond to modern interpretations of sluggish liver or gallbladder function. Classical texts sometimes included Hu Zhang in formulas for jaundice or biliary stasis, suggesting an association with the gallbladder, but not specifically for post-cholecystectomy (gallbladder removal) support. There is limited scientific research directly evaluating Hu Zhang for gallbladder function or for people without a gallbladder. Most modern studies on Hu Zhang center on its main bioactive component, resveratrol, and its cardiovascular, anti-inflammatory, and antioxidant effects. Some preclinical studies suggest that resveratrol and related compounds may influence bile secretion, but there is no robust clinical evidence supporting the use of Hu Zhang specifically for gallbladder sluggishness or after gallbladder removal. In summary, the use of Hu Zhang for gallbladder issues is justified primarily by traditional practice rather than modern scientific validation, and the supporting evidence is limited and mostly indirect.