Impact of Hair Damage on the Penetration Profile of Coconut, Avocado, and Argan Oils into Caucasian Hair Fibers

The study evaluated the penetration of argan, avocado, and coconut oil into hair fibers and their impact on hair structure. In virgin hair, argan oil increased flexibility, while avocado and coconut oil reduced it. In bleached hair, all oils reduced mechanical parameters, with argan oil having the most significant impact. The fatigue test showed that in bleached hair, avocado and coconut oil treatments increased resistance to fracture, while argan oil treatment reduced it. In virgin hair, all tested oils increased the premature rupture of fibers. The oils' penetration profiles were analyzed at different depths of the hair fiber, with coconut oil identified at a higher intensity in depths beyond 30 µm in both hair conditions. The oils' triglyceride composition influences their affinity with hair, which varies depending on the hair's damage condition. The study concluded that all three oils can penetrate and interact with the hair cortex, but their effects vary depending on the hair's condition.