Hair is subjected all year round to various external factors that weaken it: the heat of the hairdryer, UV rays, pollution, swimming pool chlorine, sand and sea salt... These different elements can damage the structure of the hair fibres, alter their colour and promote the occurrence of split ends, each to their own extent. By reinforcing the hydrolipidic film that naturally coats the hair, hair oils form a first line of defence between the fibres and environmental aggressions.
The protective action of coconut oil, a vegetable oil sometimes used to formulate hair oils, has been demonstrated in a study. This research highlighted that its application before and after the shampoo significantly reduced the protein loss from hair, whether it was intact or damaged. By coating the fibres with a film and penetrating the cuticle, the lipids contained in hair oils protect the hair scales from the detergent agents present in most shampoos.
Furthermore, hair oils are often formulated with antioxidant plant oils. They can thus help to combat oxidative stress, which is harmful to the fibres. Indeed, free radicals attack various components of the hair, such as the lipids of the cuticle, but also proteins like keratin and melanin. These oxidative damages cause a loss of strength and elasticity in the hair, making it drier and more prone to breakage. To protect them, it is recommended to use a hair oil once or twice a week, according to the instructions provided on the care product.