Pyrrosia, particularly Pyrrosia lingua, is a fern commonly used in Traditional Chinese Medicine (TCM). Its use for "debility" is rooted in traditional practices rather than modern scientific validation. In TCM, Pyrrosia is often included in herbal formulas intended to "clear heat," "promote urination," and "nourish yin." Debility, as understood in the context of TCM, often refers to states of general weakness, fatigue, or deficiency of vital substances such as yin or fluids. Pyrrosia is sometimes prescribed for conditions manifesting as debility, especially when accompanied by symptoms like dryness, thirst, or urinary problems.

However, there is a lack of robust scientific studies directly evaluating Pyrrosia’s efficacy in treating or supporting general debility as defined in modern medicine. The available evidence supporting its use is primarily anecdotal and based on centuries of traditional use, rather than on controlled clinical trials or pharmacological research. A few phytochemical studies have identified constituents in Pyrrosia species with potential antioxidant and anti-inflammatory properties, but these do not specifically address the treatment of debility. Therefore, while its use is justified by tradition, the quality of evidence is modest and should be interpreted with caution.