I'm sure everyone knows that vitamin C is good for us. Today, we would like to talk about it in detail, because vitamin C is one of the most effective nutrients for our skin.
Let's start with its main effects.
▶ Benefits of Vitamin C
When free radicals, resulting from internal/external stress, accumulate in the form of activated oxygen in our body, they disrupt healthy skin cells and cause aging. However, the basic function of vitamin C is to eliminate this toxic free radical and prevent skin aging.
[Reference] Vitamin C inhibits TNF-induced activation of NF-kB through activation of p38 mitogen-activated protein kinase, J Immuol. 2000 Dec 15;165(12):7180-8
When our skin is exposed to UV, the melanin cell deep within the skin produces melanin pigment and discoloration occurs, such as freckles and spots. Vitamin C blocks this melanin pigmentation pathway, ultimately improving skin tone.
[Reference] Efficient hydroxylation of L-tyrosine by native and immobilized tyrosinase, PLOS ONE, 11(10): e0164213 (2016)
Vitamin C is one of the basic elements for producing collagen, an essential component of our skin. And if we lack vitamin C, collagen synthesis decreases and the skin loses its elasticity.
Therefore, vitamin C is an ingredient that replenishes collagen, improving elasticity and wrinkles.
[Reference] Vitamin C, Collagen, and Plaque Fissures, Circulation Volume 105, Issue 12, March 26, 2002; Pages 1396-1398
▶ The nature of vitamin C
Pure vitamin C is volatile and easily oxidized by various factors such as air exposure, UV exposure, pH, and temperature. As oxidation progresses, it takes on a dark yellow color, which can even turn brown when it progresses too far.
Despite its instability, vitamin C is still the most beloved ingredient due to its excellent efficacy for the skin. And to control pure vitamin C, various vitamin C derivatives have been developed and are actively used. Vitamin C derivatives are well known to be good for our skin because specific chemical reactions and enzymatic actions convert them into pure vitamin C. However, it is an early stage to ensure that vitamin C derivatives have the same effect as pure vitamin C. It needs to be clarified how it is converted and how much it does.
[Reference] Topical L-ascorbic acid: percutaneous absorption studies• Dermatol Surg 2001;27:137–142
Therefore, pure vitamin C, ascorbic acid, is the most recommended ingredient for an adequate effect.
Pure vitamin C has excellent absorption into the skin, and one study says that the amount of vitamin C increases in a short period for this reason.
We can also expect better effects when used consistently than when used just once, as it will maintain vitamin C in our skin.
[Reference] Topical L-ascorbic acid: percutaneous absorption studies• Dermatol Surg 2001;27:137–142
*So, just like we take vitamin supplements daily, it is important to consistently use vitamin C products.
To support the effect of a vitamin C product, the optimal pH must be applied, taking into account not only the vitamin C content, but also the skin absorption rate and stability.
Studies have shown that ascorbic acid is better absorbed into the skin when the pH state is stronger. [Reference] Topical L-ascorbic acid: percutaneous absorption studies• Dermatol Surg 2001;27:137–142
However, products with strong acidity are not recommended in pH conditions as they could irritate normal skin, which is slightly weakly acidic.
Considering the nature of vitamin C and our skin, the best pH condition for a vitamin C skin care product is around pH 3.0-4.5.
▶ Vitamin C products at COSRX
COSRX has two vitamin C derma products that combine pure vitamin C (ascorbic acid) in high percentages. The two products contain 13% and 23% ascorbic acid and the same active ingredients, such as tocotrienol (super vitamin E), hyaluronic acid, and allantoin. You can expect similar effects from the two products, but the two options are available for you to select based on the strength and feel you want.
*For more information about the product,
▶ Vitamin C Product Guide
Refrigerating products with high pure vitamin C content is the best way to keep vitamin C fresh. It is also highly recommended to close the cap (dropper) after using the product and keep it away from high temperatures or direct sunlight. It is best to finish using the product within the expiration date after first opening.
*Using sunscreen together adds effect when using the vitamin C product during the day.
Depending on your skin type, you may experience mild dryness or tightening of the skin after using the vitamin C product. Using a moisturizer/hydrator together will help balance the finish.
As we take vitamin supplements daily, start healthy skin care
by using cosmetic products with vitamin C. ✨
The Benefits and Importance of Vitamin C for Skin
