(CNN) -- Hundreds of women nationwide are suing the manufacturer and designer of a hair smoothing product that they say caused them severe hair loss and other damages.
At the center of the dispute is Suave Professionals Keratin Infusion 30-Day Smoothing Kit, a hair treatment product for women who wanted "smooth, shiny manageable hair with no frizz."
Josephine Wells and Catherine Reny, among some other plaintiffs in a California federal court, wrote in a lengthy complaint that the manufacturer, Unilever, knew but failed to disclose that the product "contains an ingredient or combination of ingredients that causes significant hair loss upon proper application."
That California case -- filed last week and represented by the Law Office of Jana Eisinger, PLLC, as well as Morgan and Morgan P.C. -- was added to several other multimillion-dollar pending lawsuits against Unilever as well as partners LEK and Conopco. They face various claims such as personal injury, negligence and false advertising.
Unilever also failed to warn consumers of the product's potential risks to their scalp, even after it "knew or should have known of its hazards," the complaint read, adding that it instead used deceptive marketing strategies.
The product claimed to be based in keratin, a protein naturally found in hair and would not contain dangerous chemicals, but pictures attached to the complaint showed some women suffering visible bald spots, broken and discolored hair, and burned scalp.
The product, which Unilever said was discontinued last year, might still be for sale at some retailers, said Amy Davis, an attorney with Dallas-based law firm Christiansen Davis Bullock LLC that's representing some women in a New Jersey state court. More than 380,000 units were recalled, the U.S. Food and Drug Administration said.
The plaintiffs claimed the product deceivingly used an ingredient that would release formaldehyde -- a cancer-causing substance that could also lead to symptoms including irritation, skin sensitivity and breathing difficulties, according to the U.S. Department of Labor's Occupational Safety and Health Administration.
Unilever said the product was instead formaldehyde-free.
"MY BEAUTIFUL ITALIAN HAIR, is damaged from this product from HELL!!!! Like I don't have enough grief in my life, now I have had to cut off about 5 inches of my hair, I've been having to condition it every day," wrote one woman on a Facebook campaign page launched last year aimed at collecting evidence of damages.
"This product from hell needs to be removed from the market. It's false advertising/misleading advertising and ruins women's hair!!!"
In an e-mail sent to CNN on Thursday, Unilever spokeswoman Anita Larsen declined to comment on the pending litigation.
"The company takes these claims very seriously," she said. "The safety of all of our products is of paramount concern to Unilever."
Larsen added no other Suave Keratin Infusion products were affected.