Henna (Lawsonia inermis) has a long-standing history of use in traditional medicine across various cultures, notably in South Asia and the Middle East. Traditionally, henna paste or its leaves have been applied to the forehead or scalp to alleviate headaches, including those attributed to sinus issues. The rationale in folk medicine often revolves around henna's reputed cooling properties, which are believed to provide relief from heat-induced headaches and sinus congestion. In Unani and Ayurvedic systems, henna is sometimes prescribed for its anti-inflammatory and analgesic effects, though these uses are largely anecdotal and based on centuries-old practices rather than controlled studies.

From a scientific perspective, there is a lack of robust clinical evidence supporting the efficacy of henna for treating headaches or sinus-related symptoms. Some laboratory studies have identified anti-inflammatory and mild analgesic properties in henna extracts, but these findings have not been translated into clinical trials specifically targeting headache relief. There is also no consensus in the biomedical literature about the mechanisms by which topical application of henna could relieve sinus headaches. As such, while henna's use for this purpose is documented in traditional medical systems, scientific validation remains minimal.