When we think of proteins, we often associate them with our muscles. However, they are the fundamental building blocks of our entire body. Muscles, hormones, antibodies, haemoglobin, skin, hair… Proteins are everywhere!
Keratin is a fibrous, helical (spiral-shaped) protein that forms the main structure of our hair, nails and skin. It is produced naturally by our bodies from amino acids. It is not found directly in our diet.
Keratin is the most abundant protein in the hair fibre. It is made up of 18 amino acids, including cysteine and methionine, two sulphur-containing amino acids.
Rich in sulphur and fibrous in nature, keratin takes the form of long, strong fibres that coil around one another to form a structure that is solid, resilient and supple all at once. It therefore ensures that our hair is waterproof, protected, resistant to damage and shiny. Finally, it also acts as a heat shield, up to around 100 °C.
Keratin is not replenished within the hair: it is gradually depleted over the course of the hair’s life. Unfortunately, factors such as ageing, an unhealthy diet and excessive exposure to stress can cause keratin levels to decline more rapidly, resulting in hair and nails that are brittle, dull and prone to breakage.
