3 keratin treatment side effects for curly hair that you should know

mujer de pelo rizado con gesto de desconfianza

Some of the possible side effects of keratin treatment on curly hair are:

  • Side effect 1: You may permanently lose your curls.
  • Side effect 2: As curly hair is more prone to breakage, the treatment could cause irreversible damage.
  • Side effect 3: As the keratin treatment is sealed with heat, high temperatures could ruin your hair.


YOU MAY ALSO BE INTERESTED IN: How long does keratin treatment last on curly hair?

Keratin Treatment For Curly Hair: before and after, reviews and side effects


I know what you’re thinking.   If keratin treatment can have such negative side effects on my curly hair, why should I apply it?  


My answer is this: before applying keratin treatment to your curly hair, you should talk to your stylist.

  Your curly hair’s health depends on that.  


In other words, you should talk to your stylist and be completely honest with your treatment expectations.

What do I mean?

estilista trabajando en cabello de clienta

  • For example, you could mention that you want a keratin treatment that doesn’t modify the curly structure of your hair.
  • You could ask if there are other treatments to repair your curly hair.
  • You can also ask how much formaldehyde the keratin treatment has.
  • Most importantly, if you want to keep your hair curly, how long will the straightening effect last after the treatment?


YOU MAY ALSO BE INTERESTED IN: 4 Formaldehyde-free keratin treatment side effects


If your stylist understands your expectations and empathizes with your fears, you won’t get any unpleasant surprises with keratin treatment on your curly hair.


Many salons use keratin treatments that contain more formaldehyde than necessary. Of course, they’ll leave your hair straight longer.

Generally,   the curls come back after two weeks after applying the keratin treatment.  


But if the salon you have chosen or the treatment you will apply at home is too strong, there’s a chance that the curls won’t come back.

That is, your new hair will grow curly, but the hair with keratin will remain straight.

So, before you apply keratin treatment to your curly hair, you should know what could happen. I’ll tell you about that.


YOU MAY ALSO BE INTERESTED IN: Why is my hair still curly after keratin treatment?


Side effect 1: Your curly hair may be straight after keratin treatment

antes y después de la keratina en pelo rizado

To avoid this,   you should check if the keratin treatment you chose contains formaldehyde and how much it has.  


YOU MAY ALSO BE INTERESTED IN: Does a keratin treatment straighten your hair?


The more formaldehyde in the treatment, the longer its effects will last. Almost all treatments that modify or repair the hair structure, such as straightening, keratin, and even some perms, contain this chemical ingredient.

How do you recognize it? By the smell. If you have a treatment with a large amount of formaldehyde, you’ll feel discomfort in your eyes and throat as soon as it is sealed with a flat iron.


I also want to clarify that keratin isn’t dangerous. Actually, keratin is the main protein in your hair and the one that curls it. When you apply a Keratin treatment to your curly hair, you fill in the parts of your hair fiber where that protein is missing.

However, keratin treatment leaves the hair straight.   If you want to keep the shape of your curls, you should talk to your stylist about applying a keratin treatment that will leave your hair straight for two to three weeks.  

This way, you’ll repair your hair, but keep its curly shape.


Side effect 2: Keratin treatment can damage your curly hair

pelo difícil de desenredar

  The Keratin treatment is sealed with heat up to 450° F or 260° C.   That’s a lot of heat for curly hair.


Also, curly hair is more prone to breakage. So, the the stylist should assess your curly hair to see if it will withstand the process.

A professional stylist will know if your hair will withstand the keratin treatment or if it’ll break during the process.

If the stylist doesn’t even look at your hair and directly offers you the appointment, look for another salon.

That way, you’ll avoid damaging your hair irreversibly.


Side effect 3: Keratin treatment could break curly hair

sellado de la keratina

While hair breakage is a risk of all chemical processes with heat, in the case of curly hair, the risks are greater.

Let me give you an example.


Let’s imagine you need to stretch a metal spring. How will you do it?

You can’t hammer it because you’ll deform it. You can’t put it in a press because you’ll crush it. Instead, if you use heat, you can stretch it gradually and mold it until it’s completely smooth.

The same goes for your curls.


During the keratin treatment, your hair will be straightened. Then, it’ll be sealed with a flat iron.

However, your hair may not resist the process. In that case, the keratin won’t fill the empty spaces to be flexible enough to stretch.

So, after the first wash, your hair will start to fall.

This is very serious. You’ll need a treatment to stop hair loss due to breakage with products that strengthen the molecular bonds of the hair, such as OLAPLEX 7 BONDING OIL or REDKEN BONDING SHAMPOO.



Before applying a keratin treatment to your curly hair, you should ask a professional stylist. If you apply a keratin treatment with formaldehyde, your curls may not be recovered.

Your stylist can recommend other professional treatments to repair your curly hair.

Deja Tu Comentario