Siberian cocklebur (Xanthium sibiricum), also known as Cang Er Zi in Traditional Chinese Medicine (TCM), has a long history of use as a remedy for nasal and sinus issues. In TCM, it is considered an important herb for "dispelling wind" and "opening the nasal passages." It is commonly included in formulas like Cang Er Zi San, which is used to address symptoms such as nasal congestion, sinus headache, and rhinitis. The traditional rationale is based on centuries of observational use rather than modern scientific validation.

Scientific research on Siberian cocklebur’s effects on sinus health is limited, with only a few preclinical studies suggesting possible anti-inflammatory or anti-allergic properties. However, these studies are not robust enough to confirm efficacy or safety in humans for sinus support. There is also some concern regarding toxicity, as certain compounds in the plant can be harmful at high doses. Overall, while Siberian cocklebur’s use for the sinus system is well-established in traditional medicine, current scientific evidence does not strongly validate its effectiveness for this purpose.