I would give this zero stars. My daughter is a hair dresser we followed the directions exactly. It honestly ruined my natural curly hair. If you have any color on your hair which I did be prepared for it to all be stripped and have to pay for a whole new color and highlights bc it turned my brown hair with golden highlights a bizarre orange! My hair stylist could not believe it. Then it took my big barrel curls and made my hair flat with with no curl just non uniform waves, straight, slightly curly with no real improvement on frizz. It looks so bad. I end up in a pony tail or bun every day. I have had several other Keratin treatments and never experienced this. Also the product burned my scalp, I ended up washing it out 12 hrs later I could have never left it in 48 hrs. Thank goodness I didn’t bc I believe I would have hair loss from the trauma it would have caused my hair and scalp. I am now using a PH balance shampoo to slowly wash the keratin off bc I hate it. My hair has never been thru so much from one bad product. I am so disappointed with this product and I even ordered a shampoo with my treatment that I am now scared to use bc I don’t trust the company. I tried to save money by doing this at home, it would have been much cheaper for me to pay the salon cost bc I have spent hundreds trying to make my hair normal again!