I have curly hair of decent length (6+ inches on the top), and while I use a small amount of light product every day and rinse my hair daily, I only wash it once to twice a week. When I received this shampoo, I was a little disappointed, just because my hair is certainly not thinning, but decided to try it to see if it had any other positive effects.
The first thing I noticed was that this shampoo did not clean my hair thoroughly -- within 36 hours, my hair was as greasy and felt dirty in a way that it usually takes up to a week to reach between washes with my go-to Paul Mitchell shampoo. As someone who prefers not to wash every other day, this was a significant downside for me.
I can't speak to the anti-thinning aspects of the shampoo, but from a basic quality-of-clean standpoint, I can't really recommend it.