A traditional Chinese herbal root used for centuries to “blacken hair and nourish essence” is drawing fresh scientific interest for hair loss, according to a review published in the Journal of Holistic Integrative Pharmacy and covered by ScienceDaily. The review of laboratory research, clinical reports, and historical herbal records on Polygonum multiflorum, also known as he shou wu, points to several possible mechanisms, including blocking the hormone most associated with pattern hair loss, protecting hair follicle cells, activating growth-signaling pathways, and improving scalp circulation. The authors are careful to note that stronger clinical evidence is still needed, since large human trials haven’t been conducted and much of the current support comes from laboratory and historical sources rather than controlled studies. They also stress that preparation, dose, and quality all affect the herb’s safety profile, and that self-treatment without professional guidance isn’t advised.