Fo-Ti (Polygonum multiflorum, also known as He Shou Wu) has a long history of use in traditional Chinese medicine (TCM) for supporting hair health and addressing hair loss or premature graying. In TCM, Fo-Ti is believed to nourish the liver and kidneys, which are thought to play a role in hair vitality. Historical texts and anecdotal reports cite its use for restoring color to gray hair and promoting hair growth.

However, scientific evidence supporting these traditional claims is minimal. A small number of laboratory and animal studies suggest that Fo-Ti extracts may stimulate hair follicle activity or promote hair regrowth, but these findings have not been robustly replicated in well-controlled human trials. No large-scale clinical studies have definitively shown Fo-Ti to be effective for hair loss or thinning in humans. Furthermore, concerns about potential liver toxicity and other side effects have been reported in the medical literature.

Therefore, while Fo-Ti is widely used in traditional practices for hair health, the evidence supporting its efficacy is based primarily on historical and anecdotal data rather than rigorous scientific validation. The overall quality of evidence is low, and caution is recommended due to safety concerns.