Perfect for: A+ exfoliation
Why: This cult serum is found on copious bathroom shelves around the world. Why? Well, its hero ingredient, glycolic acid, is a great all-rounder that most skincare routines would benefit from. In essence, it delves into the skin and exfoliates dead skin cells, unclogs pores, evens skin tone and (over time) minimises the appearance of fine lines. Plus, the potent formula doubles up as a targeted treatment mask – apply a thick layer for ten minutes and let it work its magic.