The US’ top-selling skin care brand Rodan + Fields is being called to defend one of its products in court, according to a report published by CBS News.

In a federal class action lawsuit, the direct sales firm is charged with violating Californian consumer protection laws and engaging in fraudulent and unfair marketing of its Lash Boost eye serum. The row centers over the key ingredient employed in the serum, isopropyl cloprostenate with the plantiffs claiming that Rodan + Fields failed to disclose the possible side effects that could be caused through use of prostaglandin analogs, the group to which this ingredient belongs.

“Consumers of Lash Boost… have experienced serious side effects, including change(s) in iris colour, eyelid drooping, itchy eyes, eye/lid discoloration, thinning and loss of eyelashes/loss of eyelash hair, eye sensitivity, eye infections, and vision impairment,” reads the filing, per CBS News.

“Rodan + Fields provides clear directions to users, including those who experience irritations,” the company said in a statement, adding that it would ‘let the specifics’ of its legal defense ‘play out in court’.