I started using Wen based on a recommendation. I noticed immediately that I was losing a lot of hair in the shower and during styling, but I thought this was a natural shedding process and tried to be patient.
I have a lot of hair - very long, and very thick - so I am used to a significant amount of natural shedding, but the amount of hair that I was losing each time I used the Wen product was frightening.
After a particularly bad reaction (I actually lost a CLUMP of hair), I did some research and learned of this phenomena. I would not recommend Wen to anyone, even though this only happens to a small group of people, the damage was so significant I would not want to risk trying it in the first place.