It has to be the biggest beauty mystery facing millennials – when is the right time to start an anti-ageing routine? Go in too early and you risk overloading the skin with too-rich products, or blasting already unbalanced skin with ingredients that are far too harsh for any complexion straight out of high school. On the flipside if you wait too long, those lines already creeping their way across your forehead will have travelled too far to be reversed and they’ll have invited friends along for the ride. “Many of my clients in their 20’s are concerned with ageing, which makes sense as the skin starts to age from the young age of 21,” explains skin therapist, Jocelyn Petroni, who says the biggest concern facing women under 30 is sun damage and dehydration. “Usually when we first become concerned with ageing and see our skin looking older it’s because we see dehydration lines. Treating dehydration instantly makes us look younger and more youthful.” As one of Australia’s leading skin experts, we asked Petroni for the four must-have products every girl in her twenties should have in her bathroom cabinet.