Lomatium, particularly Lomatium dissectum, has a long history of traditional use among Native American tribes and herbalists as a remedy for respiratory ailments, including congestion and sinus issues. The root was commonly prepared as a tea or tincture to help with coughs, colds, influenza, and sinus problems. The traditional rationale is that Lomatium possesses expectorant and antimicrobial properties, helping to thin mucus and support the body in clearing respiratory passages.

However, there is minimal modern scientific research validating these uses. Few laboratory or clinical studies have been conducted on Lomatium for sinus or respiratory congestion. The available evidence consists mainly of ethnobotanical reports and anecdotal accounts. Some in vitro studies suggest mild antimicrobial and anti-inflammatory effects, but these are not directly tied to clinical relief of sinus congestion. As such, while its use is well-established in traditional herbal medicine, the evidence from rigorous scientific studies remains very limited.

In summary, Lomatium’s use for sinus congestion is primarily supported by traditional and historical usage rather than strong scientific validation.