A hair relaxer marketed by top notch celebrities from Cynthia Bailey to first lady Michelle Obama is the target of a new U.S. class-action lawsuit amid allegations that the product actually causes hair loss.

The L’Oreal product, which promises “fuller, silkier hair” causes “disturbing and distressing injuries including hair loss and breakage as well as scalp irritation, blisters and burns,” according to the lawsuit, which was filed Wednesday in a California federal court.

There are already 100,000 plaintiffs, said attorney Ben Meiselas, who is known for representing celebrities like Michael Jackson in court, according to Agence France-Presse. Meiselas estimates that the penalties could reach into the hundreds of millions of dollars range but that he is willing to start settlement talks if the French cosmetics giant is interested.

“It’s up to them if they want to avoid a trial,” Meselas told AFP.

The product in question is a no-lye hair relaxer that has been marketed under the Soft Sheen-Carson brand. The suit was marketed primarily to black women.

L’Oreal defended the product. “Relaxers are technical products that can be used safely according to the instructions,” a company spokeswoman said.

The suit alleges that the product, which was said to include a derivative of Indian gooseberry, is filled with a “dangerous mix of irritants and potentially toxic substances” instead of the advertised oils.

“Plaintiff is currently wearing partial hair pieces to cover up the areas of hair loss and is currently purchasing costly hair vitamins to help her hair regrow,” the suit says, referencing Sharon Manier of California, one of the plaintiffs whose name is on the lawsuit.

Stock of L’Oreal, a massive French company that brings in 25.6 billion euros a year in revenue, did not seem to be particularly affected by the lawsuit. While declining in general this month, stock in the company has remained around 165 euros.