Phragmites australis (common reed) has a long history of use in traditional East Asian medicine, particularly in Chinese herbal practices, where it is known as "Lu Gen." It is commonly included in herbal formulas aimed at treating symptoms such as nausea, vomiting, and fever, especially those related to gastrointestinal disturbances and febrile illnesses. Classical texts such as the Shennong Bencao Jing and later pharmacopeias describe its use for quenching thirst, relieving vomiting, and clearing heat from the stomach.

The evidence supporting its effectiveness for nausea and vomiting largely comes from centuries of empirical use rather than rigorous scientific research. While some modern pharmacological studies have suggested that extracts of Phragmites exhibit anti-inflammatory and antipyretic properties, direct clinical evidence supporting its efficacy specifically for nausea and vomiting is limited. Most references in scientific literature cite traditional usage and propose potential mechanisms based on animal studies or in vitro experiments, but robust human trials are lacking. Thus, its use for this purpose is justified primarily by tradition, and the strength of evidence is modest.