Hair is comprised of the following substances:

• Proteins: main components (65-95% of hair weight). The most important protein is keratin, made up of amino acids (mainly cystine, cysteine, methionine, leucine, serine, glycine, arginine and threonine).
• Minerals and oligoelements: such as selenium, zinc, iron, magnesium, aluminium, calcium, copper.
• Water: present in variable percentage and linked both to the health condition of the shaft and the environmental level of humidity.
• Lipids (fats): their presence is principally due to the sebum naturally produced by the scalp sebaceous glands.
• Pigments: they determine hair colour, in particular melanin, which is produced by the melanocytes present in the bulb, then transferred to the hair follicle cells. The different hair colors are genetically determined and vary according to type, quantity and distribution of melanin: eu-melanin gives shades from brown to black; feo-melanin from blond to light and reddish brown; tri-codestrine, a variant of feo-melanin, is present in blond and red hair.