WEN is getting slammed with claims that the product, intended to help hair, can actually make it fall out.
Last month, more than 200 women in 40 states joined a class action lawsuit filed against hair care line WEN by Chaz Dean, claiming the products caused severely and possibly irreversible damage to their hair and scalps.
Brooke Shields, one of the endorser swears by the WEN haircare line, calling the shampoo and conditioning products her "new must-haves." Other fans include actresses Angie Harmon and Ming Na-Wen.
On its website, the brand says it's different from any other hair care product in that it "cleanses and conditions the hair simultaneously."
"The cleansers include a perfect blend of special ingredients, including natural botanicals and herbs, and do not contain sodium laurel sulfate or harsh chemicals," company's bio said.
The brand was created by celebrity hairstylist Chaz Dean, who first made it in his kitchen.
Dean is listed as a defendant in the lawsuit along with marketing company Guthy-Renker.
In, a statement provided to NBC News, Wen, Guthy-Renker and Chaz Dean rebutted the claims, saying, "There is no scientific evidence to support any claim that our hair care products caused anyone to lose their hair."
There are many reasons why individuals may lose their hair, all unrelated to Wen hair products.
The product was advertised as a sulfate-free alternative to shampoo, that can replace shampoo, conditioner and other products, the products works as a "shampoo, conditioner, deep conditioner, detangler and leave-in conditioner.
In the court documents, a woman named Amy Friedman says she bought the Wen Sweet Almond Mint basic kit in January of 2014 for $29.95 and two weeks later, her hair started falling out.
The consumer was stopped using the product soon after, but ended up losing "one-quarter to one-third" of her hair, and was forced to spend a great deal of money on hair extensions to covered her baldness.
Despite the lawsuit, there are still thousands of positive reviews from customers who have enjoyed the WEN product.
