Umckalin is a coumarin compound found in the roots of Pelargonium sidoides, a plant native to South Africa. Traditionally, extracts of this plant (often referred to as Umckaloabo) have been used in folk medicine to treat respiratory tract infections and related symptoms, including those associated with the Eustachian tubes, such as ear congestion and middle ear infections. The rationale is that Pelargonium sidoides preparations may help reduce inflammation and support the immune response, thereby potentially facilitating mucus drainage and relieving pressure in the Eustachian tubes.

While there is some clinical evidence for Pelargonium sidoides extract in the management of acute bronchitis and sinusitis, direct scientific validation of Umckalin or Pelargonium extracts specifically for Eustachian tube dysfunction is limited. Most existing studies focus on their general effects on upper respiratory tract infections rather than targeted support of the Eustachian tubes. Therefore, the use of Umckalin for Eustachian tube support is justified primarily by traditional use, with only indirect or anecdotal scientific support.

In summary, the historical and ethnobotanical use of Pelargonium sidoides forms the basis for its association with Eustachian tube health, but robust clinical evidence for this specific indication is lacking.