Straight to the Point: What Do We Know So Far on Hair Straightening?
January 2021
in “
Skin appendage disorders
”
TLDR Hair straightening can damage hair and pose health risks, including exposure to carcinogens and hair loss.
The review article, based on 33 relevant articles from MEDLINE through PubMed, examined various hair straightening methods, their effects on the hair shaft, and associated health risks. It described how physical methods like hot combs and flat irons temporarily alter hair structure, while chemical straighteners such as hydroxides and thiols permanently change the hair's keratin. The article highlighted the dangers of Brazilian Keratin Treatment (BKT) due to its use of formaldehyde, a known carcinogen. A study cited within the document found that all 23 Brazilian hair straightening brands exceeded safe formaldehyde levels, with some containing 18-54 times the permitted limit. Alternatives like glyoxylic acid can also release formaldehyde at high temperatures. Adverse effects from hair straightening include dermatitis, hair loss conditions like telogen effluvium and traction alopecia, and hair breakage. The conclusion emphasized the need for dermatologists to be informed about hair straightening practices to advise patients on minimizing risks and seeking safer, "ethical straightening" options.
