Vitamin C in skincare

Vitamin C is one of the top most beneficial ingredients that you can incorporate in your skincare.
With an excellent safety profile, it's been proven effective time and time again against photo ageing, hyperpigmentation, skin inflammation and skin healing. I can't wait to tell you about the benefits of vitamin C in Korean skincare because I honestly believe it's the best thing you can give your skin. Everyone should be using vitamin C in their skincare. Here's why. 

Antioxidant – UV Protection

When skin is exposed to UV light, free radicals are formed that start a chain reaction that eventually leads to skin cell damage. Antioxidants terminate these chain reactions by neutralizing free radicals. Vitamin C is a well-known antioxidant. It is equally effective against both UV A and UV B. Even though using sunscreen is the #1 skincare staple for UV protection, sunscreens only block 55% of free radicals produced by UV exposure. To optimize UV protection, it’s important to use sunscreens in combination with topical antioxidants like vitamin C. Unlike sunscreens, vitamin C does not block the formation of free radicals, but neutralizes free radicals, an effect not seen with sunscreens. For an even higher antioxidant performance, you could use vitamin C in conjunction with vitamin E, which increases the action of vitamin C four-fold. But more about vitamin E in another post.

Collagen Synthesis

In addition to its antioxidant functions, vitamin C also keeps the skin young and firm by being a key player in the synthesis of collagen. Collagen is the main protein in connective tissues all over the body, from skin, to cartilage, to bones. It acts like a glue that keeps cells together and gives the body form and support. Collagen is what gives the skin its strength and elasticity. Vitamin C is involved in virtually every step of collagen production. It directly activates collagen production, leading to quantitatively more collagen. But it is also responsible for stabilizing and cross-linking collagen molecules, qualitatively improving the structure of collagen molecules, which eventually leads to a firmer and stronger skin. So vitamin C not only leads to more collagen, but also structurally stronger collagen.

Depigmenting agent

Vitamin C is also known to be an effective skin-brightener by tackling hyperpigmentation. Vitamin C interrupts key steps in the production of melanin, avoiding pigmentation, resulting in a brighter complexion.

Anti-inflammatory

Vitamin C inhibits the activation of inflammation. This is particularly interesting for those with acne vulgaris and rosacea. Vitamin C also helps inflamed skin by promoting wound healing (through collagen production) and preventing post-inflammatory hyperpigmentation.

All in all, Vitamin C is a true Korean skincare superhero. 

Vitamin C formulations

Vitamin C can be incorporated into skincare formulations in several forms:

Ascorbic acid (also known as L-ascorbic acid)
Magnesium ascorbyl phosphate
Tetrahexyldecyl ascorbate
Ascorbyl palmitate
Ascorbyl glucosamine
Ascorbyl tetraisopalmitate.

All have been proven to be active and effective if properly formulated. Magnesium ascorbyl phosphate is the most stable form. It's fat soluble, so it is easily absorbed into the skin. But the most well-researched form of vitamin C is ascorbic acid. That is why most skincare products are formulated with ascorbic acid.
It’s important to note that the efficacy of vitamin C is proportional to the concentration, but only up to 20%.

How to use Vitamin C

The biggest disadvantage of any antioxidant is that they are extremely unstable and vulnerable to destabilizing when exposed to light and air. So make sure that you use only those products that are packaged protected against light and air. This means preferably an opaque tube or a pump. Also make sure that your vitamin C product has a pH of less than 3.5. Because vitamin C is most stable below that range.  

Vitamin C is safe to use on a daily basis alone or in conjunction with other topical anti-ageing agents like sunscreens, tretinoin (retinol), alpha hydroxyl acids (AHA’s), and other antioxidants like vitamin E. Just make sure that your skin can tolerate the combinations. Since UV light denatures vitamin C, topical vitamin C is best used at night after sun exposure. Be careful when using vitamin C around the eyes.

Have you tried any vitamin C products? What results did you see? I hope this post has been helpful to you!

References
Indian Dermatology Online Journal, June 2013, pages 143-146
Clinical, Cosmetic, and Investigational Dermatology, September 2015, pages 463-470
Journal of the American Academy of Dermatology, September 2008, issue 3, pages 418-425
Journal of the America Academy of Dermatology, November 2012, pages 1103–1024