Effect of Hair Straightening Treatment on Porosity and Cysteic Acid Content of Hair

Background: Chemical straightening has increased in popularity because of its durability over thermal straightening and because it gives the hair a natural smooth, shiny look, more styling options for a longer time. The aim of this study was to evaluate the degree of damage that occur to the hair after chemical straightener treatment by assessing the change in hair porosity and hair cysteic acid content before and after straightener treatment.

Methods: Forty hair samples were collected from female volunteers; each sample was divided into 2 groups; group A (before straightening) and group B (after straightening). Hair samples were washed then blow dried after that hair straightener was applied for 30 min then flat iron was done, hair samples were washed and blow dried. Each group was subjected to test their porosity and Fourier transform infrared spectroscopy examination to assess cysteic acid content.

Results: Hair porosity showed significant increase after straitening. Cysteic acid and disulfide content showed insignificant difference between both groups.

Conclusion: Hair straighteners may cause great damage to hair internal structures. So, proper choice of the material used and assessing the hair characters before straightening is necessary.