At your ripe age, you're probably well aware of the dietary importance of vitamin C. But that’s not its only value. According to consultant dermatologist Dr Anjali Mahto – and anyone else who’s been paying attention – “vitamin C in skincare has gained much popularity in recent years.” And “with a great number of scientific studies that support its use in a daily routine,” this isn’t a passing fad. Here’s everything you need to know about it and the vitamin C serums that matter.
“Vitamin C is primarily an antioxidant that protects the skin against free radical damage resulting from environmental factors such as sun exposure and exposure to pollution and environmental toxins such as cigarette smoke,” says holistic aesthetic doctor and GP, Dr Rabia Malik. But “there are many types of vitamin C which can be found in skincare,” Dr Anjali notes.
“The metabolically active form of L-ascorbic acid should be considered the gold standard for topical vitamin C. It is most effective at a concentration of 10-20%,” she says. However, its effectiveness may come at a cost: “in higher percentages it can cause irritation especially in those with sensitive skin.” Luckily, there are weaker, more stable derivatives of vitamin C in skincare that are suitable alternatives if this is the case. If you want to get seriously scientific, they include ascorbyl palmitate, ethyl ascorbic acid, magnesium ascorbyl phosphate, ascorbyl tetra-isopalmitoyl, and sodium ascorbyl phosphate.
There are several! Well, four in particular. “Firstly, it will aid collagen synthesis,” says Dr Anjali. Essentially, this means that “regular use after 6 months can help reduce the appearance of fine lines.” Then, there’s also the fact that continued use of vitamin C over 8 weeks can help fade dark marks on the skin. Why? “Vitamin C works by blocking an important enzyme known as tyrosinase, a key player in the processes that lead to pigmentation.” As previously mentioned by Dr Rabia, it also functions as an antioxidant and neutralises damage caused by harmful molecules known as free radicals. “Left unchecked, these can damage the DNA, proteins and lipids in our skin leading to premature skin ageing,” adds Dr Anjali. For Dr Rabia, “most people will benefit from the antioxidant protection offered by vitamin C, but especially those who are outdoors for prolonged periods of time and smokers” (unsurprisingly). Lastly, “vitamin C has the benefit of being anti-inflammatory and can help reduce redness or irritation in conditions such as acne.”
Well, it depends. “Serums are superior because their texture and formulation allow for increased absorption and penetration, but vitamin C is notoriously unstable so exposure to UV light can decrease the potency of a serum over time,” says Dr Rabia. The aforementioned – by Dr Anjali – “L-ascorbic acid in powder form is a very effective format for vitamin C,” she says. And its potency can also be reduced by mixing it “into a number of other products such as a hyaluronic acid serum or a moisturiser.”
Furthermore, Dr Anjali urges us to “not fall into the trap of thinking expensive is better when it comes to vitamin C.” She recommends opting “for a product where vitamin C is high on the [ingredients] list rather than towards the very end.” It is also important to note that other antioxidant ingredients like ferulic acid and vitamin E can improve the stability or effectiveness of vitamin C, so popular vitamin C serums may feature a combination of these. Another factor to consider is that “vitamin C is very unstable and breaks down rapidly on contact with air.” Because of this, it’s worth choosing “a product which is ideally in opaque or dark packaging with an airtight seal,” she advises. “After purchase, store your product out of direct sunlight in a cool, dry place – a hot steamy bathroom is not the place” for it (although we’re sure you can briefly place it there for an impromptu photo shoot).
“In the morning, after cleanser and before moisturiser, to allow for protection against free radical damage, UV exposure and environmental exposure throughout the day,” says Dr Rabia. Don’t forget to put SPF on top, though.
Vitamin C is a notoriously unstable (and somewhat bratty) ingredient, so compatibility with other actives is not known for being one of its strengths. However, Dr Rabia tells us that “hyaluronic acid is a good companion for vitamin c as the two ingredients work together synergistically.” As they say, there’s someone for everyone.
As the acne treatment benzoyl peroxide “can oxidise vitamin C and make it less potent” – according to Dr Rabia – this combination is best avoided. While vitamin C and retinol “can yield great results,” the road to them can be one of great skin sensitivity and irritation if the formulations aren’t quite correct.
“It is possible to overdo it with almost any skincare ingredient, including vitamin C,” says Dr Rabia. “If your skin becomes irritated or starts to break out after using a vitamin c product, this could suggest you are using too much.” Reduce it so that your skin is able to establish a better tolerance over time.