Keratin straightening: who it suits, and how long it lasts
Keratin straightening is the service that attracts the most misconceptions. It does not straighten hair permanently, and it does not damage it the way the old chemical relaxers did — it sits somewhere between the two.
What it actually does
The treatment puts keratin — the hair’s own protein — into the surface layers of the shaft, then sets it there with heat. That makes the surface of the hair smoother and more uniform.
The visible result: less frizz, faster drying, a shinier surface. The wave does not disappear entirely, but it becomes far easier to manage.
Who it is worth it for
Anyone whose hair reacts to humidity immediately and who fights it every morning. Anyone with thick hair that takes forever to dry. And anyone for whom the straightener is a daily tool — because after the treatment the daily heat load drops, and over time that is worth more than what the treatment itself costs the hair.
It is not worth it for someone who likes their natural wave, nor for someone fresh out of a heavy lightening session: better to let the hair recover first.
How long it takes, and how long it lasts
The appointment runs about three and a half hours. Depending on how often you wash, the result lasts three to five months, then wears off gradually — not as a hard line the way colour grows out, but as a slow return to the original texture.
The first few days
The period straight after matters most. Your stylist will give you the exact instructions, since they depend on the product, but broadly: for the first few days avoid tight elastics, tucking hair behind your ears, and ponytails — the hair is still settling into its new shape.
After that, sulphate-free shampoo. Sulphate washes out exactly what the treatment was for.
What to ask beforehand
Ask which product they use and how much formaldehyde it contains — most salon products today are formaldehyde-free, but it is worth clarifying. Ask, too, whether they would recommend it at all given the current state of your hair.
If you are unsure, a consultation is a good way in here as well: a quarter of an hour is enough to work out whether this treatment will do for your hair what you want from it.