Mondo Grass (Ophiopogon japonicus), known as "Mai Men Dong" in Traditional Chinese Medicine (TCM), has been historically used for various medicinal purposes. Its primary uses in TCM are to nourish yin, moisten the lungs, and benefit the stomach, rather than for supporting the bladder specifically. However, formulations containing Mondo Grass are sometimes used to address symptoms such as dry mouth, irritability, and certain urinary tract discomforts, which may be interpreted as related to the bladder system from a traditional perspective.

The traditional rationale stems from the herb's believed ability to replenish bodily fluids and address conditions of dryness or "yin deficiency," which can, in some TCM frameworks, contribute to urinary symptoms. Despite its frequent use for other organ systems, there is some traditional precedent for its inclusion in herbal formulas aimed at promoting urinary comfort, though this is not its most prominent historical indication.

Scientifically, there is very limited direct research on the effects of Mondo Grass on bladder health, urinary tract function, or related pathologies. Most studies focus on its antioxidant, anti-inflammatory, and possible anti-diabetic properties. Therefore, the justification for its use in supporting the bladder system relies mainly on traditional use, with little to no high-quality clinical evidence directly supporting this specific application.