My dermatologist laughed when I told him about all the messages on the boards that said Wen caused their hair to fall out and the follicles were being "blocked". He told me nonsense...unless the rare person has a true allergy to an ingredient, there is nothing in Wen that is going to cause hair loss...told me not to believe everything I read! Also, he told me his wife is a "Wen girl".
What he did say is that you need to rinse Wen two or three times longer than you would a regular shampoo.
Hope this helps someone....
