The US Food and Drug Administration (FDA) is investigating several claims that a line of cleansing conditioners marketed under the brand WEN by Chaz Dean have caused hair loss, balding and skin irritation, according to a report published by NBC New York.

To date, the FDA has received 127 adverse event reports from consumers; the largest number of reports ever associated with any cosmetic hair cleansing product. In addition, the US regulatory body, has discovered more than 21,000 complaints were submitted directly to stylist Chaz Dean, who fronts the range, and manufacturer Guthy Renker.  

“We have confidence in WEN by Chaz Dean,” Guthy-Renker told NBC in a statement on Monday. “We have no evidence that WEN, or any of the individual ingredients in WEN, causes hair loss. WEN is used by hundreds of thousands of satisfied customers, and all formulations of the product comply with applicable regulations wherever it is sold. We have consistently cooperated with the FDA with respect to any enquiries regarding WEN and we intend to continue to do so.”

The FDA is calling on consumers who have experienced issues with the Cleansing Conditioners line to cease use of the product and to seek medical advice as well as report any reactions they have experienced to the FDA.