The honest truth about Brazilian keratin

Keratin smoothing is the most over-promised service in the salon industry. Here is what it actually does, and what it does not.

What it does

A good keratin smoothing reduces frizz dramatically and cuts blow-dry time in half for 3 to 5 months. It makes hair shinier and easier to style. Curly hair becomes a relaxed wave; wavy hair becomes nearly straight.

What it doesn't do

It does not "repair" damaged hair. It coats the cuticle, which feels healthier, but it does not rebuild bonds. If your hair is already over-processed, smoothing on top will eventually crack the cuticle and leave you worse.

The formaldehyde question

Old-school Brazilian keratin used formaldehyde and produced fumes that were rough on stylists and clients. Modern reputable formulas are formaldehyde-free or contain very low levels — but cheap "no-name" kits sold online frequently lie on the label. Asking a stylist which brand is used, and to see the SDS sheet, is reasonable and informative.

Who should skip it

Pregnant and breastfeeding clients (most reputable salons defer treatment until later), anyone with hair already at 60 % or more breakage from prior bleaching, and anyone who actually wants their natural curl pattern preserved.