4 citations,
June 2016 in “PubMed” Repeated dyeing and shampooing cause hair color loss and damage.
56 citations,
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69 citations,
January 2002 in “Journal of biomedical optics” Dyes can penetrate human skin and hair follicles up to 1.2 mm deep and the sebaceous gland can store dye; Indocyanine Green lotion was made for safe dyeing and monitoring.
44 citations,
April 2003 in “European journal of pharmaceutical sciences” Lipophilic dyes accumulate more in hair follicles when delivered with surfactant-propylene glycol solutions.
191 citations,
November 1959 in “Annals of the New York Academy of Sciences” Hair and wool have complex microscopic structures with microfibrils and varying cystine content.