best keratin for hair treatment please? help?

[happywithit]

my hair is unmanageable, i decide to use the keratin but don't know which one as i heard they are the one that very dangerous is well, i want just the one that have the best staff inside, doesn't matter the price.
please help

I had the Keragreen one a few years back and it was advertised as formaldehyde free. I didn't know that formaldehyde can be labelled as other chemicals. After having it done I found that it contained 3%. It had a very faint smell but as I've had cancer I was annoyed as I wanted to go down the natural route and not use a potential carcinogen. People on here recommend the Amazon kit but personally I wouldn't use it as the smell is really strong that would put me off.

thank you for the advice,sorry to hear your experience, wish you a good health.