Gallesia integrifolia, commonly known as "pau d'alho" in Brazil, has a traditional history of use in South American folk medicine, particularly for respiratory conditions such as congestion, coughs, and colds. The plant's roots, bark, and leaves are often prepared as teas or decoctions to alleviate symptoms of nasal and chest congestion. This use is largely attributed to its strong, garlic-like odor, which suggests volatile sulfur compounds similar to those found in garlic (Allium sativum), another plant traditionally used for respiratory issues. Ethnobotanical surveys in Brazil and neighboring countries have documented its use by indigenous and rural populations for various ailments, with congestion being among the most commonly cited.

However, there is limited scientific research directly evaluating the efficacy of Gallesia integrifolia for congestion. Some studies have identified antimicrobial and anti-inflammatory activities in extracts of the plant, which could theoretically contribute to relieving respiratory symptoms, but these findings are preliminary and not specific to clinical outcomes in humans. Overall, the use of Gallesia for congestion is primarily supported by traditional knowledge rather than robust scientific validation.