According to an article on CNN.com:

"Olaplex, a beauty brand favored by TikTok and Instagram influencers, sells hair products that dozens of customers allege caused “serious injury,” according to a lawsuit filed last week. Olaplex denies the claims, saying independent test results prove the allegations to be false."

'Nearly 30 women joined together to file a lawsuit against Olaplex on February 9, specifically targeting its No. 0 to No. 9 products. They allege the products caused hair loss, breakage, brittle hair, bald spots and scalp irritation."

Photo Credit: David Williams/Bloomberg/Getty Images

"The customers say in the lawsuit that Olaplex use ingredients that can cause allergic reactions and are banned in Europe"

In response to the lawsuit, an company spokesperson for Olaplex said  “We have publicly released test results from independent third-party laboratories, going above and beyond industry standards, to demonstrate this. We have full confidence and believe in the safety and efficacy of our products,” 

"The plaintiffs are seeking more than $75,000 in damages."

Source:  CNN.com - Olaplex Hair Product Lawsuit