have use both Brazilian Blow out and Coppola, I would reccomend neither, what I have found by doing extensive research is GKhair taming system. There system is very versatile, curl girls who love their curls but hate frizz can still have their curls, and those with the curliest hair who hate their curls can get rid of up to 80% leaving it very manageable and allowing them to straighten it completely on their own. It is the best system out there with the best keratin that is the closest match to human hair, allowing it to penetrate deeper and last longer
I worked in salon where they try all the system in search of one that didn't make the staff dizzy and all of these made everyone including the receptionist very sick every time brazilian blowout,keratin complex,GK,SIMPLY SMOOTH,Rejuvenol,we did however tried "KeraGreen" by organic color system and it work every well and no one got sick,hope this helps you,I no longer work in salon that provide this service,so I don't know about the new products.
While some may not have FORMALDEHYDE in them, you need to check what ALDEHYDES they have. Some become FORMALDEHYDE at a certain temperature. Copola was one of them that I used and researched. Not good. And frankly, I resented that they weren't 100% truthful with me on that and I finally had them send me an MSDS sheet. Ya want to know the worst part of it? When I called them to question why I was smelling a STRONG odor of formaldehyde, and they told me it's free of it, I was working on a client who was a cancer survivor.
I now use GK. Just take time to do your own research and don't rely on just opinions.
Have used Keratin Complex for 5 years and have never had any bad results from the treatments or dissatisfied clients. It is Amazing!