COSRX consumer research center has studied consumer reviews, researching vitamin C in efforts to discover new insights into the ingredient. And what they found was that consumers use vitamin C in anticipation of all the positive improvements it can bring about. Unfortunately its unique irritating and stinging sensation have led to many with sensitive skin having to stop its use. In fact, the words "irritating & stings" have been repeated time and time again.

In response to this, COSRX, the hypoallergenic brand for sensitive skin poured through research papers, carrying out study upon study to finally develop a concentrated vitamin C derm serum with maximum effectiveness and minimum irritation.

Highly concentrated vitamin C serums are notoriously difficult to manufacture as they are susceptible to oxidation caused by external conditions and are prone to exploding due to internal gas generation. To prevent this, the highly concentrated pure vitamin C formula is contained in a specialized bottle that allows to expel gas whilst blocking the inward flow of oxygen.

💡Here are some frequently asked questions you would like to know.


Efficacy of Main Ingredient

 Q1.What does vitamin C serum do for you?
-Aging and environmental damages can decrease vitamin C levels in the skin, vitamin C skincare products can help supplement.
-Capable of inhibiting reactive oxygen species formation by functioning as an electron donor
-Essential ingredient for stimulating ceramide production and building up skin barrier
-Reduce active inflammation
-Essential cofactor for promoting collagen synthesis
-Stimulate collagen genes and collagen production
-Stimulate elastin genes and elastin production
-Inhibit the formation of melanin without skin toxicity and make skin lighter by improving hyperpigmentation and blemishes


Q2.How does work Vitamin C for skin?
-Vitamin C is one of the best anti-aging ingredients and helps your skin brighter while inhibiting the formation of melanin. It’s good for anti-aging and improving skin elasticity by increasing in collagen and elastin production.

 

Efficacy of Sub Ingredients

Q3.What does Tocotrienol(Super Vitamin E) do to your skin?
-Have 50 times higher antioxidant than tocotrienol
-Stimulate collagen synthesis in skin fibroblasts
-Stimulate collagen genes more than tocotrienol


Q4.What does Sodium Hyaluronate do to your skin?
-Attract moisture in skin cells and increase skin hydration
-Decrease wrinkle depth and improve elasticity
-Prevent sagging skin and wrinkles caused by UV rays and make skin look smooth
-Stabilize skin structures by regulating water balance and ion flow


Q5.What does Allantoin do to your skin?
-Promote skin repair by working mechanism of wound healing
-Stimulate collagen production to repair skin
-Enhance antioxidant ability by inhibiting reactive oxygen species formation


Application

Q6.Can I use vitamin C serum every day?
-This is a higher concentration of pure vitamin C, so it may come with skin irritation. We recommend you patch test back of the wrist, or on your neck before first use. It can be used every day, however if your skin feels irritated, please apply the product less frequently at first before increasing the frequency. If your skin feels severe irritated, we recommend you use with a moisturizer but if your skin still feels irritated, please apply the product less frequently or stop using it.


Q7.What should you not mix with vitamin C?
-Mixing with hydroxy acid such as AHA, BHA may cause severe skin irritation, however our products with low concentrations of hydroxy acid are good to use together after allowing your skin to adjust.


Q8.What can vitamin C be mixed with?
-Tocotrienol, hyaluronic acid, ceramide, snail, centella


Q9.Do you put vitamin C before moisturizer?
-Vitamin C is the best to use before skincare. If you use a light water serum-type C serum first and then cover it with a thick cream type, you can absorb more vitamins into your skin.

 

Side effects

Q10.Does vitamin C serum darken skin?
-Help your skin brighter while inhibiting the formation of melanin


Q11.Why does vitamin C burn or sting, turns reds my face?
-This is a higher concentration of pure vitamin C, so it may come with skin irritation. We recommend you patch test back of the wrist, or on your neck before first use. It can be used every day, however if your skin feels irritated, please apply the product less frequently at first before increasing the frequency. If your skin feels severe irritated, we recommend you use with a moisturizer but if your skin still feels irritated, please apply the product less frequently or stop using it.