Since launching in 2014, Olaplex has become the go-to brand for hair repair. The company, with its patented technology designed to essentially reconnect broken hair bonds, paved the way for an entire category around ‘bond repair hair-care — and it has resulted in countless imitators to boot. But now, Olaplex is facing legal trouble due to customer complaints accusing the enormously popular products — which raked in $176 million in sales last year as of the third quarter — of causing dryness, damage, and breakage, with some users even reporting hair loss.

Olaplex denies all of the above: “Olaplex products do not cause hair loss or hair breakage,” the brand wrote to Refinery29 via email. “Olaplex products are safe and effective, as millions of our customers can happily attest.”

Furthermore, according to Bessam Farjo, a hair restoration surgeon at the UK’s Farjo Hair Institute, due to the cosmetic regulations that all companies have to comply with, hair products are proven safe for use — or they just wouldn’t be on the shelves. “Hair products are tested vigorously, and standard shampoos and [conditioners] don’t cause hair loss,” says Dr Farjo. “Only severe chemicals would cause such damage. If something is irritating to the hair, you’re more likely to get temporary damage to the outside of the hair, rather than near the root.”