Bioactive Nutritional Macromolecules Supporting Hair Structure, Density, and Growth: A Comprehensive Review

March 2026 in “ Cosmetics ”

Johannes‐Paul Fladerer, Selina Fladerer-Grollitsch

type I collagen elastin keratin ceramides melanin extracellular matrix hair follicle tensile strength UV protection collagen hair matrix hair strength hair resilience hair color

TLDR Type I collagen, elastin, keratin, ceramides, and melanin improve hair strength, growth, and health.

This review examines the roles of five macromolecules—type I collagen, elastin, keratin, ceramides, and melanin—in enhancing hair structure, density, and growth. Type I collagen and elastin support the hair follicle's extracellular matrix, promoting growth and reducing breakage. Keratin improves tensile strength and reduces shedding, with clinical studies showing a 30–50% decrease in hair loss. Ceramides maintain moisture balance and structural integrity, while melanin provides UV protection and maintains color. Clinical trials confirm these macromolecules' effectiveness in improving hair health, despite some limitations in study populations and sample sizes. The evidence supports their combined use to enhance hair strength, resilience, and overall health.

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