Kim Kardashian "can't live without" it. Britney Spears uses it for "finishing touches." Hillary Duff takes it "everywhere." And Jennifer Lopez just says "no to dry lips."
"The rise of EOS has been meteoric and it's been fueled by social media," said attorney Ben Meiselas.
But EOS — the trendy lip balm in the brightly colored little ball — is now the subject of a class-action lawsuit over the potential for allergic reactions.
Meiselas, who filed the suit, said adverse reactions to the celebrity-endorsed product affect potentially hundreds of thousands of people.
"Mine is one of the most extreme cases," said Racheal Cronin, the "face" of the lawsuit. "I had the dryness, flakiness, burning, itching, cracking and bleeding."
The 24-year-old said she experienced a severe reaction after using EOS's "summer fruit" lip balm and went online searching for answers.
"I found thousands of people talking about same results," Cronin said.
Meiselas said complaints have flooded message boards, dermatology websites and even EOS' own Facebook page.
"They are looking back at the consumer and saying, 'We hear you, but we're ignoring you,'" Meiselas said. "And that's a problem."
Listed among the lip balm ingredients is shea butter, which is derived from shea nuts and designated by the FDA as a food allergen.
"We were truly shocked that there was absolutely no warning anywhere to be found," Meiselas said. "This company thinks in this social media age they can skirt consumer protection laws."
Meiselas said this kind of cyber campaign and celebrity endorsement amount to viral marketing — minus the responsibility.
"Do you have to, as a corporation, provide warnings on your Instagram and Twitter — if you are going to reach out to consumers in such an aggressive manner? Do you have an obligation to provide warnings? I think you absolutely do," Meiselas said.
The lawsuit demands warnings on the packaging and online, which Cronin said could save some people painful bumps, blisters and embarrassment.
"I'm angry that they don't have a warning because I never would have purchased this product if I'd known this could happen," Cronin said.
She said it took 10 days for her face to clear up.
But EOS said the lawsuit is "without merit." The company released a statement saying its products "are made with the highest quality ingredients and meet or exceed all safety and quality standards set out by our industry and validated by rigorous testing conducted by an independent lab."
EOS added that "millions of satisfied customers" use its product daily and said customers' "health and well-being is our top priority."