15 citations
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October 1970 in “Archives of disease in childhood” Hair amino acid levels can indicate metabolic disorders.
December 2025 in “Universal library of medical and health sciences.” Amino acids like arginine and cysteine protect hair during chemical treatments, keeping it strong and less brittle.
76 citations
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December 2011 in “Journal of Cell Science” Different keratin types have unique amino acid patterns that are evolutionarily conserved.
38 citations
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May 2000 in “Livestock production science” Giving high-quality protein or methionine supplements helps improve hair growth in Angora goats and, to a lesser extent, in Cashmere goats.
5 citations
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May 1983 in “Australian journal of biological sciences” Certain amino acid analogues can inhibit wool and hair growth and affect fiber strength.
March 2005 in “Journal of the American Academy of Dermatology” Adding amino acids to damaged hair can improve its strength and appearance.
12 citations
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July 2017 in “International Journal of Cosmetic Science” N‐AOHPA is a promising alternative to traditional surfactants for better hair conditioning.
5 citations
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October 2007 in “PubMed” Amino acids in conditioners improve hair strength, hydration, and color retention.
4 citations
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December 2018 in “Macedonian Journal of Chemistry and Chemical Engineering” A new method accurately measures amino acids in treated hair, showing bleaching reduces amino acids while protein treatments increase them.
24 citations
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April 2016 in “Experimental Dermatology” Chemical treatments like dyeing, perming, and bleaching damage hair by altering amino acids and lipids.
2 citations
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January 1981 High temperatures and certain chemicals can significantly change the amino acid content in human hair.
September 2025 in “Journal of Surfactants and Detergents” Shampoos with sodium lauroyl methylaminopropionate improve hair lubrication and reduce irritation.
88 citations
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July 1958 in “Nature” Citrulline was found in hair follicle proteins for the first time.
39 citations
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February 1990 in “The journal of cell biology/The Journal of cell biology” Trichohyalin, a hair follicle protein, has a part with repeating patterns of 23 amino acids.
18 citations
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October 2018 in “Nutrients” Annurca apple extract promotes hair growth by changing hair follicle metabolism to boost keratin production.
3 citations
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June 2012 in “Korean Journal of Human Ecology” The supplement reduced hair loss and increased hair thickness safely.
1 citations
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January 1996 Cysteine and arginine are essential for hair growth and thickness.
April 2024 in “Current research in nutrition and food science” Taking an amino acid supplement improved skin, hair, and nail health in women.
June 2023 in “Skin Research and Technology” The supplement with amino acids, iron, selenium, and marine hydrolyzed collagen improved hair growth more than drug treatment alone, with most people tolerating it well.
4 citations
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December 1989 in “The Journal of Dermatology” Human hair proteins have similar cysteine and glycine levels to skin proteins.
13 citations
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October 2008 in “PubMed” Japanese women's curved hair has an uneven internal structure and varying amino acid composition.
11 citations
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November 1966 in “Experimental Biology and Medicine” Hair diameter can indicate protein status in malnourished children if sample location is controlled.
July 2009 in “International Journal of Cosmetic Science” Japanese women's curved hair has an uneven internal structure and varied amino acid composition.
February 2025 in “International Journal of Cosmetic Science” A new amino acid derivative, ATS, improves hair texture and moisture, making it easier to straighten curly hair.
January 2011 in “Yearbook of Dermatology and Dermatologic Surgery” Hair relaxers are linked to reduced cystine levels and potential hair damage.
Using enzymes to link proteins makes hair repair treatments more effective and long-lasting.
12 citations
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August 1984 in “Genetics Research” The N gene affects the protein makeup of mouse hair.
March 2022 in “Annals of Bariatric Surgery” Protein supplements with zinc, iron, and B vitamins reduce hair loss after sleeve gastrectomy.
January 1974 in “Nippon Nōgei Kagakukaishi/Nihon Nougei Kagakkaishi” Applying L-methionine and L-serine to the skin promotes the most hair growth.
1 citations
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April 1977 in “Munich Personal RePEc Archive (Ludwig Maximilian University of Munich)”