English Horsemint (Mentha longifolia), also known as wild mint, has a long history of traditional use for various respiratory and digestive complaints. In herbal medicine, it has been used to support the mucus membranes, particularly in the context of soothing sore throats, coughs, and minor respiratory tract irritations. The plant contains essential oils, including menthol and pulegone, which are thought to have mild expectorant and soothing properties. Historical texts and ethnobotanical surveys indicate its use in teas and infusions for relieving symptoms related to excessive mucus and inflamed mucous membranes in the mouth and throat.

However, scientific studies specifically investigating English Horsemint's effects on mucus membranes are limited. Most modern research focuses on related species such as peppermint (Mentha piperita) or spearmint (Mentha spicata). The evidence supporting its efficacy is thus primarily anecdotal and based on traditional usage rather than rigorous clinical trials. There are some in vitro studies that suggest antimicrobial and anti-inflammatory effects of Mentha longifolia extracts, which could theoretically benefit mucosal health, but this evidence is preliminary and not directly linked to the use in humans for supporting mucus membranes.

In summary, the use of English Horsemint for supporting the mucus membranes is primarily justified by traditional herbal practices, with limited direct scientific validation.