1 citations
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May 2013 in “PubMed” This study found that glycylglycine treatment improved hair softness by enhancing hair alignment and altering internal fiber properties among Japanese women with typically coarse hair.
April 2019 in “Digital Library of Theses and Dissertations (Universidade de São Paulo)” This study found that the acidic hair straightening formulation at pH 1.0 improved hair alignments and straightening effectiveness more than pH 2.0, but it weakened fiber strength and affected hair color and composition.
June 2026 in “Institutional Repository of the Federal Technological University of Paraná (RIUT) (Federal University of Technology – Paraná)” This study found that leave-in hair formulations with macadamia oil, especially at a 3.33% concentration, may improve frizz control and maintain stability, suggesting potential benefits for hair appearance.
11 citations
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June 2013 in “PubMed” This study found that controlled thermal straightening can achieve irreversible smoothing of curly hair without chemicals, with effectiveness dependent on temperature and cycles, and silicone enhancing straightening quality.
January 2026 in “International Journal of Cosmetic Science” This study identifies key attributes—luminosity, structural integrity, and vitality—that define hair vibrancy, providing insights to guide the development of hair products that align with consumer expectations.