What does vitamin C do?
It might be quicker to list what it doesn’t do… As one of the most potent antioxidants, vitamin C protects against environmental damage (including pollution), brightens skin tone, boosts collagen and inhibits pigmentation. “I rate it top among all ingredients,” declares leading dermatologist Dr Dennis Gross. “And it’s best used topically – the amount you would have to ingest to have the same level of antioxidant benefit for the skin would be toxic. Plus, it stimulates collagen as the fibroblasts (which create new collagen) have receptors for vitamin C so it enhances the cell’s DNA to make more.” Vitamin C is also said to have skin-brightening qualities, as Angela Adjei, head of product at 111Skin, explains: “Any resurfacing is very mild, and I certainly wouldn’t put it as an obvious benefit, but it does block the abnormal production of pigmentation, which gives that brighter-looking complexion.”
What to look for
As with other potent actives (including retinol), this is where things get tricky, because different brands choose to use different types of vitamin C. Ascorbic acid, or L-ascorbic acid, is the pure, natural form of vitamin C; it is also the most researched and the most unstable. “But whichever type is used depends on the rest of the product formulation and its delivery system,” says Dr Gross. This is the one product where packaging actually matters: look for sealed, airless pumps; darker tinted bottles; encapsulated powder (I love the Dr Sebagh Pure Vitamin C Powder Cream); or single or short-use ‘shots’, all of which help to ensure that the active ingredient is kept at its most potent. “Also think how you use and keep it,” says Adjei. “Keep the lid on and don’t leave it out on a bathroom shelf where the fluctuating heat from a shower or bath can degrade it. If it does change slightly in color from oxidization, you can still use it – it shows it’s a good concentration – but any more obvious changes and it’s probably best to discard it.”
Know your %
Although proven to be active from just 0.6%, the higher the percentage the more serious the effects. But as you up the concentration you can also increase any sensitivity, so whatever results you are looking for the best advice is start low and go slow. “But irritation is the only downside,” reassures Dr Gross. For daily use, to get a generally brighter skin tone and to provide a good antioxidant back-up to your daily SPF, anything up to or around 5% is enough. You can also try a vitamin C face wash or wash-off mask to reduce any skin irritation (I love Lixirskin Vitamin C Paste, and Joanna Vargas Vitamin C Face Wash for a brilliant morning skin brightener). “But some people can feel that skin tingle even at 2%,” says Adjei. “If so, then use it with a face cream. From 10% and up, it gets more active. You can use this two or three times a week but, ultimately, it’s about being consistent and using it regularly for at least eight weeks – that’s when you really see results.” To tackle sun spots, you need to work up to around 20% – the level clinically shown to be effective.
How to use it
Although usually recommended for the morning – to protect skin from pollution, in particular – with this smart multitasker there are no hard and fast rules, so you can still use it at night. “Just make sure it’s part of your regular, ongoing routine,” says Adjei.
Probably the easiest way to use it is in a serum (or a powder mixed into a serum). “For me, that’s the best delivery system,” says Dr Gross. “It’s often paired with vitamin E, which acts to further enhance the antioxidant properties of vitamin C.” And, not that you should need reminding, don’t forget to use your SPF. “Why use a high-percentage vitamin C and not use SPF?” asks Adjei. “You are trying to treat your pigmentation but all you would be doing by forgoing SPF is exposing your skin to more of it.”