When it comes to tackling discolouration on the skin, the Biossance Squalane + Vitamin C Dark Spot Serum (£49) is a triple threat. In addition to 10 percent vitamin C, the serum contains licorice root extract, which inhibits the production of an enzyme needed to produce melanin (pigment) in the skin (it also helps remove excess pigment). The formula also includes a white shiitake mushroom extract, an ingredient the brand claims also helps fade dark spots.