Depends on which kind of treatment you doing. Under the same name, you can find completely different things.

this said, in gva, it's MOSTLY keratin+ formol, and if you just want to put down/control some waves, it looks really good. But if you hair is too curly, will not straighten much. And if you want a completely straight hair in the end, this is also not the solution.....

Shaun:

Not the sort of reply I was expecting but you made me smile…

Wanessa:

Thank you very much for the clarification.

Does it damage the hair at all?  Also how long does it usually last for (I have fine and wavy hair)

Hi, i did the keratin almost since 2 month, i have fine, wavy and colored hair, and it didn’t damage my hair. Before I had a lot of problems with the relaxing and colouring, I was losing my hair, but now even i see new hair coming because i got this treatment (in my case). What you need every time you wash your hair to use the brushing as usual. I am very happy with it, even with the rain or the humidity it still good. You will be surprise how it easy your life with it Also in Switzerland they don’t allow the use of formal, because it very dangers for the body. So go for it girl and if you need further info  I can give it to you,

Can you use any shampoo?

You can use shampoo, but one without salts and neutral pH to keep longer the chemicals (yes, they do have a tiny bit of formol, I asked the hairdresser, he couldnt deny it. but way less then in brazilian formulations). Im using a shampoo from Sebastien, but i guess any supermarket has some other options.

Depending on how often you wash, and the products you use, it lasts from 2 to 4 months. In my case, I even dont need to dry/brush after shower. I just let it dry naturally.

And compared to all the other treatments, this is the one that damages less the hair. in fact, because of loads of keratin, it's even better after.

Rowhi, Wanessa:

How waved was your hair - from 1 to 5 - before the treatment?

1 being japanese straight and 5 being curly curly? i'd say 3, but roots are mostly straight....

Does it damage the hair?