Well, I purchased the advanced formula considering the seller's persistance..
I do not recommend it!
Fumes were so strong that I could bearly stand them, my eyes were watering during all the procedure (even when I was applying the product on my hair)
Even when I had finished the flat ironing, my hair had an irritating smell all the time before I wash it out.
(I m regularly using QOD original and I had very very little irritation, nothing like this one)
I thought that this great amount of formaldehyde should provide better results compared to other keratines I've tried before. But I was wrong.
Hair came out straight and soft, but just for the following 5-10 days
Then,although it remaind straight enough, it started to get dry more and more, and was rough to touch and a bit frizzy.
What's more, my hair colour (blue-black) faded a lot after the procedure.
I should have bought Inoar as I was planning to do...