The theory of applying glycolic acid first or nicotinamide
The way to nourish the skin, glycolic acid and nicotinamide are both important for skin care. However, there are different opinions on the order of application, so it is necessary to study in detail.

Glycolic acid has the power of rejuvenation. It can loosen the connection between keratinocytes, make old keratin fall off, make the skin surface renewed and radiant. However, it is slightly stronger. If the skin is already sensitive, use it rashly, or cause discomfort, such as redness and tingling.

Niacinamide can regulate the oil secretion of the skin, improve dullness, and strengthen the skin barrier. It is mild in nature and suitable for all kinds of skin.

If the skin is well tolerated, glycolic acid is applied first to open the skin channel and make subsequent niacinamide absorption better. First use glycolic acid to rejuvenate the skin, exfoliate its old keratin, and then use niacinamide to nourish and repair, complementing each other.

However, those with sensitive skin should first use niacinamide to nourish the skin and strengthen the barrier. When the skin is in a stable state, use glycolic acid as appropriate. Otherwise, the skin is prone to adverse reactions due to glycolic acid stimulation, which will damage skin health.

Therefore, if you want to nourish the skin, you should carefully determine the order of applying glycolic acid first or nicotinamide first according to your own skin characteristics. This cannot be decided overnight, and it takes time to try before you can achieve the wonders of skin care.