TLDR Reflectance spectroscopy can noninvasively track hair growth stages by measuring skin reflectance and melanin changes.
In 2014, researchers conducted a study on 30 female C57BL/6 mice to evaluate hair follicle stages noninvasively using reflectance spectroscopy. They measured skin diffuse reflectance and analyzed melanin content, finding that reflectance was high during the telogen and early anagen stages, decreased during anagen progression, and increased again during catagen. Melanin content showed inverse patterns, with a 6% increase on day 5 and over 60% on day 11, followed by a decrease during catagen and reaching a minimum during telogen on day 23. These results, consistent with histological examinations, suggest that reflectance spectroscopy could be a valuable tool for monitoring hair follicle stages and evaluating hair regeneration treatments, with data supported by a sample size of n ≥ 9 for each measurement.
305 citations,
June 2012 in “Nature” Hair regeneration needs dynamic cell behavior and mesenchyme presence for stem cell activation.
60 citations,
April 2012 in “Physiology” The document concludes that understanding hair and feather regeneration can help develop new regenerative medicine strategies.
176 citations,
April 2011 in “Science” Hair stem cell regeneration is controlled by signals that can explain different hair growth patterns and baldness.
240 citations,
April 2011 in “Pigment Cell & Melanoma Research” Melanocyte stem cells in hair follicles are key for hair color and could help treat greying and pigment disorders.
64 citations,
January 2009 in “The International journal of developmental biology” Hair follicle stem cells are controlled by their surrounding environment.
520 citations,
February 2001 in “Journal of Clinical Investigation” VEGF helps hair grow and determines follicle size by increasing blood vessel growth.
21 citations,
May 2022 in “Frontiers in Cell and Developmental Biology” Hair growth and health are influenced by factors like age, environment, and nutrition, and are controlled by various molecular pathways. Red light can promote hair growth, and understanding these processes can help treat hair-related diseases.
