Evaluation of Human Hair Absorption and Retention

Objective: Adequate nutrition and moisture are crucial for preventing hair loss and maintaining hair health and appearance. Hair loss (alopecia) affects up to 50% of the population, causing significant social and psychological impacts. Despite the popularity of hair care products and their ingredients known to be beneficial, existing methods for evaluating the absorption of these substances into hair remain limited. This study assesses the absorption and retention of nutrients and moisture within human hair via 3D Raman spectroscopy. Methods: Three variables were structured for a double-arm study, involving untreated hair, water-treated hair, and hair treated with a supplemental hair care product. Hair samples were analyzed for absorption amount, depth, and dryness at 30 min intervals using Raman spectroscopy with 3D imaging technology. Results: Hair treated with hair care product indicated significantly higher in absorption amount, deeper penetration, and reduced dryness, confirmed by statistical analysis ( p < 0.05). After 30 min of treatment, hair care product-treated samples maintained their absorption parameter, amount, depth and dryness ( p < 0.05). This was further validated by the 3D Raman visualization which provided detailed spatial distribution and retention of absorbed substances within the hair fibers over time. Conclusion: These findings demonstrate the superior absorption and retention of hair care product in hair compared to untreated and water-treated hair, setting a new standard for evaluating hair absorption and product efficacy. Our method offers a promising tool for future clinical research and hair care product development.