Effects of Chemical Straighteners on the Hair Shaft and Scalp

The study reviewed 33 articles from 2000 to 2020 on the effects of chemical straighteners on the hair shaft and scalp. It found that these straighteners, including formaldehyde and its derivatives, can cause scalp issues like eczema, desquamation, pain, burns, and inflammation, as well as hair shaft damage such as hair loss, reduced resistance to breakage, color changes, and altered amino acid composition. The effects vary based on hair type and specific chemicals used, with Afro hair being more resistant but still susceptible to damage. Sodium hydroxide increases oxidative alterations and cysteine damage, and straighteners are linked to inflammatory scalp changes and conditions like cicatricial alopecia. Conditioning agents can mitigate some damage but may reduce straightening effectiveness. The review highlights the need for further research to understand the long-term consequences of chemical straightening and emphasizes the importance of awareness among health professionals.