Initially... Unfortunately, the quantity seemed insufficient to me... It was enough for one application on my hair, and that was with sparing use. Now, the worst part... Firstly, during application, the smell that came out when I used the straightening iron was unbelievably intense... But I could tolerate it. What I unfortunately couldn't tolerate at all was the result. Firstly, the color of my hair, being dyed, changed by 2 shades and became a dark coppery blonde... The second and worst of all was that even though I only used sulfate-free shampoo afterwards, as recommended, the desired straight hair lasted for only 2 washes. Then we went back to the previous state. The only difference being the color and the condition of the hair, which, although not initially visible, became terrible within a month of application. Something that never happened to my hair since I generally don't mistreat it. So... Clearly, I believe it's not worth the effort, time, and money for this endeavor...