research Age-Dependent Changes in Damage Processes of Hair Cuticle 20 citations, January 2015 in “Journal of cosmetic dermatology” Older people's hair cuticles get more easily damaged and lose protective oils, especially in their 40s and 50s.
research Hair Cosmetics: An Overview 193 citations, January 2015 in “International journal of trichology” Dermatologists need to understand hair products to treat hair and scalp issues better.