Vitamin C (VC) is a common whitening ingredient in cosmetics, but there are rumors that using VC-containing cosmetics during the day will not only fail to whiten the skin, but will also darken the skin; some people are worried that using skin care products containing VC and nicotinamide at the same time will cause allergies. Long-term use of VC-containing cosmetics will make the skin thinner. In fact, these are all misunderstandings about VC-containing cosmetics.
Myth 1: Using it during the day will darken your skin
VC, also known as L-ascorbic acid, is a natural antioxidant that can be used to treat and prevent skin sunburn. In cosmetics, VC can slow down the synthesis process of melanin such as dopaquinone by interacting with copper ions at the active site of tyrosinase, thereby interfering with the production of melanin and achieving the effect of whitening and removing freckles.
The formation of melanin is related to oxidation reactions. As a common antioxidant, VC can inhibit oxidation reactions, produce a certain whitening effect, enhance skin repair and regeneration capabilities, delay aging, and reduce ultraviolet damage to the skin. VC is unstable and is easily oxidized in the air and loses its antioxidant activity. Ultraviolet rays will accelerate the oxidation process. Therefore, it is recommended to use VC-containing cosmetics at night or away from light. Although the use of VC-containing cosmetics during the day may not achieve optimal results, it will not cause the skin to darken. If you use VC-containing skin care products during the day, you should protect yourself from the sun, such as wearing long-sleeved clothes, a hat, and a parasol. Artificial light sources such as incandescent lamps, fluorescent lamps, and LED lamps, unlike ultraviolet rays, do not affect VC, so there is no need to worry about the light emitted by mobile phone screens affecting the effectiveness of VC-containing cosmetics.
Myth 2: Long-term use will make the skin thinner
What we often refer to as “skin thinning” is actually a thinning of the stratum corneum. The essential reason for the thinning of the stratum corneum is that the cells in the basal layer are damaged and cannot divide and reproduce normally, and the original metabolic cycle is destroyed.
Although VC is acidic, the VC content in cosmetics is not enough to cause harm to the skin. VC will not make the stratum corneum thinner, but people with thinner stratum corneum usually have more sensitive skin. Therefore, when using VC-containing whitening products, you should first try it on areas such as behind the ears to check if there are any allergies.
Cosmetics should be used in moderation. If you use them excessively in pursuit of whitening, you will often lose more than you gain. As far as VC is concerned, the human body’s demand and absorption of VC are limited. VC that exceeds the necessary parts of the human body will not only not be absorbed, but can also easily cause diarrhea and even affect coagulation function. Therefore, VC-containing cosmetics should not be used excessively.
Post time: Dec-15-2023