If there’s one haircare product that’s taken the beauty world by storm, it’s Olaplex . It’s become the go-to solution for dry, damaged hair and is a bestseller for multiple retailers like John Lewis and Look Fantastic. But it turns out Olaplex No.3 Hair Perfector, until recently, contained an ingredient that has been linked to infertility. It sounds very alarming – but should Olaplex users be worried? Here’s what you need to know.