头发白了，还能变黑吗？医生的答案出乎意料！

Core Viewpoint - The article discusses the causes of premature graying of hair and the potential for reversing this condition, emphasizing the importance of scalp health and the effectiveness of a specific hair care product developed by a team from Peking University [6][10][30]. Causes of Graying Hair - Hair color is determined by melanocytes in hair follicles, which produce melanin. Loss of function or number of these cells leads to gray or white hair [6]. - Two main categories of causes for the loss of melanocyte function are identified: pathological (e.g., follicle atrophy, chronic scalp inflammation) and physiological (e.g., genetic factors, aging) [7][10]. - A study of 467 individuals with premature graying found no significant correlation between premature graying and factors such as obesity, alcohol consumption, coffee intake, stress, or emotional health [10][12]. Potential for Reversing Graying - Hair that turns gray due to pathological causes may regain color if the underlying issues are addressed, while hair that grays due to natural aging cannot be reversed [15][16]. - Improving scalp microenvironment and reducing oxidative damage can help slow down the aging process of hair follicles [17][20]. Importance of Scalp Care - The health of the scalp is crucial for the condition of hair follicles and hair. Proper scalp care is essential for effective hair care products [20][22]. - Many commercial shampoos only clean hair without adequately addressing scalp health, which is vital for nourishing hair follicles [23][24]. Product Introduction - The article introduces a hair care product, 臻玉露Rebuild生姜氨基酸润养洗发露, developed by a Peking University team, which focuses on deep cleaning the scalp and nourishing hair follicles [26][30]. - This product utilizes a patented formula that combines HAP-Rebuild repair factors with high concentrations of natural extracts like ginger juice, ginseng, and other herbal ingredients [30][50]. Product Efficacy - The product claims to effectively control oil (87.88%), reduce dandruff (81.82%), and alleviate itching (81.82%) based on third-party testing [31]. - After four weeks of use, participants reported significant improvements in scalp health, including reduced oiliness and dandruff, and increased hair volume and smoothness [82][107]. Pricing and Offers - The product is priced at 98 yuan per bottle, with promotional offers including a free trial size with each purchase and a full refund policy if not satisfied [44][136].