Pseudostellaria heterophylla, known as "Tai Zi Shen" in Traditional Chinese Medicine (TCM), is primarily used by tradition to support or treat "wasting" conditions, which in TCM are often described as body weakness, fatigue, loss of appetite, and general debility (sometimes corresponding to what is called "Xiao Ke" or "wasting-thirst" syndrome). Historical texts and modern TCM practice commonly associate this herb with replenishing "Qi" and nourishing bodily fluids, especially in individuals who are debilitated or convalescing after illness.

The evidence supporting its use for wasting is largely anecdotal and based on centuries of clinical experience documented in Chinese medical literature. While there are some modern pharmacological studies suggesting that Pseudostellaria heterophylla may have immunomodulatory, anti-fatigue, and adaptogenic effects, these studies are generally preliminary, limited to animal models, or in vitro research, and do not specifically address clinical wasting syndromes as defined in Western medicine. There is a lack of robust clinical trials in humans directly correlating the use of this herb with improvement in wasting conditions such as cachexia or severe malnutrition.

In summary, the use of Pseudostellaria heterophylla for wasting is justified by traditional use and not by strong scientific validation. It remains a staple in TCM for nourishing and restoring vitality, but evidence from modern clinical research remains limited.