Unusually for a vitamin C product, DCL's C Scape High Potency Night Booster 30 is designed to be applied in the evening rather than the morning, with a time-release system to ensure results over time. It has a 30 per cent concentration of L-ascorbic acid, making it ultra-efficacious. DCL C Scape High Potency Night Booster 30, £108. Available at Spacenk.com. A powerful combination of vitamin C, vitamin E and ferulic acid, SkinCeuticals's much-loved C E Ferulic aims to reduce the appearance of lines and wrinkles and protect skin against external aggressors. SkinCeuticals C E Ferulic, £129. Available at Skinceuticals.co.uk. Easily slotting into your regular skincare regime, Clinique Fresh Pressed Daily Booster is designed to be mixed in with your usual moisturiser both morning and night. Think of it like your daily vitamin C supplement. Clinique Fresh Pressed Daily Booster, £58 for four. Available at Clinique.co.uk. Using tetrahexyldecyl ascorbate - a stable, oil-soluble form of Vitamin C - Sunday Riley's C.E.O. Rapid Flash Brightening Serum tackles pore size, dullness, uneven tone, dehydration and more. An anti-ageing powerhouse. Sunday Riley C.E.O. Rapid Flash Brightening Serum, £70. Available at Spacenk.com. The Ordinary's original Vitamin C Suspension 23% + HA Spheres 2% product feels gritty on the skin due to the fine L-Ascorbic Acid powder that makes it so powerful. However the brand has now introduced its Vitamin C Suspension 30% in Silicone, which offers an only slightly less efficient exposure to vitamin C, but with a smoother feel. Pick your favourite. The Ordinary Vitamin C Suspension 30% in Silicone, £5.80. Available at Theordinary.com. An oil-based yet lightweight serum, Zelens's Power C aims to brighten and strengthen skin, as well as protecting it against environmental aggressors. Balancing geranium oil means it suits combination skin too. Zelens Power C Treatment Drops, £125. Available at Cultbeauty.co.uk.