After a long period of several months dealing with hair loss and a weakness of my hair to grow, I did some research and often saw this specific shampoo in the search results, so I purchased it. I can't say exactly when the change occurred (whether it was after 4 or 6 washes, for example)... I know that when the bottle finished, the condition had improved 100%, and that's how I bought 2 more. The shampoo is remarkable, and I highly recommend it.