What is a common effect of over-processing hair?

Loss of elasticity is a common effect of over-processing hair. When hair is subjected to harsh treatments such as frequent coloring, chemical relaxers, or excessive heat styling, the internal protein structure of the hair becomes damaged. This damage results in the hair losing its ability to stretch and return to its original shape, leading to brittleness and increased breakage. Healthy hair maintains a certain level of elasticity, which is crucial for its overall strength and resilience. When over-processed, the hair's cuticle may also suffer, making it more porous and susceptible to further damage, thereby exacerbating the loss of elasticity.

In terms of the other options, while improved shine and enhanced color might be the initial effects of certain treatments, these benefits are often short-lived when hair becomes over-processed. Increased strength is generally a characteristic of well-cared-for hair, as over-processing tends to weaken the hair rather than strengthen it. Thus, the loss of elasticity stands out as a direct consequence of damaging hair treatments.