I've heard about this but have no idea if the claims are valid or not. Since I"m past 60 and have hair past my shoulders, I no longer wash it everyday. I wash and condition twice a week max. I've had 2 different hairdressers tell me to do this. I used Wen a few times but didn't like the way my hair looked/felt after the first day. I think you do need to use it everyday and I don't want to wash that often. I use Pureology and really like it. No sulfates. I've recently discovered their Nano Gold formula (I think that's what it's called) and its awesome. Very expensive so I use it once every 2 or 3 weeks. I highly recommend it.