I was using this product for a year on both mine and my daughter's hair. Our hair has never even reached our shoulders so we were willing to try this out. For the first time ever I was able to grow my fringe out a bit, but the back of my hair - which always seems slower growing didn't grow much. I would say my hair has grown about an inch in a year, which for me is good (!) as it usually grows nothing at all .... sadly. I only have to get the tiniest amount trimmed off every six months or so to stop it looking frizzy. But this last year I haven't had to get it trimmed at all as I haven't had any frizz. I would say it improved the condition of my hair. I stopped using it about 3 months ago and I've noticed my hair isn't looking as nice as it was, so I plan to buy some more. As for my daughters hair, again there has been some slight growth (about half an inch) in a year, but it hasn't improved the condition, which is still frizzy. It is expensive to keep using it for so little improvement, but when you have short hair that doesn't grow, you get desperate. I think we must have an inherited 'slow growth' gene as my mother's hair was the same. The only time my hair did grow really well was when I was pregnant, so I know it CAN grow, it just doesn't want to!