I tried this product yesterday for the first time. I haven’t been able to go to the salon due to COVID-19, and my previous keratin treatment had about 1-3” of grow out. I have very fine type 3c-4a curly hair naturally and type 3a-3c hair with salon keratin treatment. My hair is highlighted, and my hair is very sensitive to brush related breakage and heat damage. With that said, I bought the $65 single pack. Although online says 6th edition, I received the 5th edition. It came with both the clarifying shampoo and the treatment. Starting with the clarifying shampoo, I needed a lot for the first wash (almost no sudsing) and very little for the second wash (lots of sudsing). My hair and my hands felt super squeaky clean, like no oil whatsoever. This is to prep the hair for the treatment. My hair is super fine, super curly, and prone to breakage with brushing so the clarifying shampoo created challenges for me since my hair got really matted. I’m pretty sure I broke off some of my hair with combing. Normally when I wash my hair, I use moisturizing shampoo/conditioner and a detangler which helps prevent breakage, this isn’t an option for this treatment because the hair needs to be prepped to take in the keratin. After towel drying my hair I applied the product in sections throughout my hair and used a fine tooth comb to ensure even coverage. I used a wet brush to comb hair prior. I clipped my hair up and put a plastic cap on my head to keep the product moist and let the product sit for 90 minutes. The product irritated my scalp a little, but I did not have any redness and it wasn’t very painful, just a slight tingling and tenderness after everything was said and done. I rinsed my hair with cold water until I could feel anymore product, towel dried my hair, blow dried it until it was mostly dry (I cannot tell what the heck is 70-80% dry, especially since curly hair still poofs when damp). I sectioned off my hair and began straightening my hair with 450F ceramic straightening iron. The first thing I noticed was steam rising. It wasn’t burning. I opened up the window since it’s the product vaporizing. This product is formaldehyde free and doesn’t have any compounds that form formaldehyde when heated, this was just paranoia on my side. I did have to run the iron over my roots a few times since they were curlier than the rest of my hair since they were virgin, I also had to run the iron over my ends a lot more than I liked because my hair is really curly and the hair needs to be straight under the iron to straighten. Because of this and the high heat, and the combing, I’m sure I had a lot of breakage and split ends. After working through my hair, I was incredibly impressed by how straight my hair was. It wasn’t as glossy as the videos but still looked great. My scalp was sensitive for most of the day but nothing too bad. My hair did feel like there was a residue on it which I guess is the product, but it wasn’t anything concerning. The best part was that this morning when I woke up, I had sweated while I slept, and there was some parts that poofed up and curled. I combed my hair and it was straight again! My regular salon keratin never did that. My roots were still flat too after sweating. It’s amazing! I’m not sure if I will go back to the salon for keratin again. I hope it lasts as long as they say (3-4 months). The only thing that wasn’t clear is if I have to keep my hair bone straight for 3 days like the regular keratin treatment or if I can wash it after 8 hours like the express keratin. I’m going to keep it bone straight for 3 days just in case.