Ingredient Guide 7 min read

All About Retinol

Retinol, also known as vitamin A, is one of the best-known fat-soluble vitamins and has been used in skincare for decades. Here is an easy guide to an ingredient we hear about a lot but often find difficult.

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By COSRX R&D Center

Key ingredient: Retinol (vitamin A)
Best for: Wrinkles, rough texture, loss of firmness
Top benefits: Smoother · Firmer · Clearer
Good to know: Use at night · Avoid in pregnancy

The Effect of Retinol

Long-term exposure to ultraviolet rays can lead to a decrease in collagen, elastin, hyaluronic acid, etc. which are essential elements that compose the skin, and retinol can fill up the skin that becomes hollow and improve elasticity and wrinkle by promoting the synthesis of decreased components in the skin.

[Reference] Improvement of Naturally Aged Skin With Vitamin A (Retinol), Arch Dermatol. 200, 143(5):606-612.

Premature aging slows the formation speed of new keratin cells, which also slows the coming off of dead keratin cells as the skin turnover cycle lengthens, andretinol can get rid of dead skin cells and improve the skin texture by promoting new keratin cells to normalize the turnover cycle.[Reference] A comparative study of the effects of retinol and retinoic acid on histological, molecular, and clinical properties of human skin, Journal of Cosmetic Dermatology, 2016, 15, 49-57.

Increasing sebum production in the pore results in skin problems like acne, and retinol can not only improve skin problems but also improve hyperpigmentation caused by skin problems by reducing sebum to suppress sebum cell propagation.

[Reference] Effects of 13-Cis-Retinoic Acid, All-Trans-Retinoic Acid, and Acitretin on the Proliferation, Lipid Synthesis and Keratin Expression of Cultured Human Sebocytes In Vitro, J Invest Dermatol. 1991, 96(5):792-7.
[Reference] An Advanced, Physician-Strength Retinol Peel Improves Signs of Aging and Acne Across a Range of Skin Types Including Melasma and Skin of Color, JDD, 2019, 1;18(9):918-923.

Characteristics of Retinol

As explained earlier, retinol has been used as a skincare ingredient for a long time because of its excellent skin efficacy. However, it is relatively difficult to make high retinol concentration because it is unstable against ultraviolet rays, and the higher the retinol content, the lower the stability. To solve this unstable problem, not only the development of various retinol derivatives but also the techniques for stabilizing retinol are constantly being studied.

[Reference] UV Irradiation and Cutaneous Vitamin A: An Experimental Study in Rabbit and Human Skin, J. Invest. Dermatol. 83, 401–404.

- Retinol and Retinol Derivative

Retinol derivatives are known to be converted to retinol by certain chemical reactions and enzyme actions and can bring an effect on the skin. However, it is a little difficult to be sure that retinol derivatives have the whole effect of retinol, as it is unclear how much can be converted to retinol in our skin by what action.

[Reference] Unoccluded Retinol Penetrates Human Skin In Vivi More Effectively Than Unoccluded Retinyl Palmitate or Retinoic Acid, Journal of Investigative Dermatology, Vol 109(3), 1997, 301-305

In fact, in Korea, retinol and retinyl palmitate(retinol derivative) are included as the Ministry of Food and Drug Safety's notification ingredients that prove to be effective in improving wrinkles, and the notification content of these two ingredients is 4 times different.

In simple language, it means that retinol derivative needs at least 4 times the amount of retinol to obtain certification for wrinkle improvement effect in Korea.

- Retinol and Retinal

Recently, an ingredient called “Retinal” is also used in cosmetics, but the ingredient that has been studied for skin efficacy for a long time is known as retinol. Therefore, the most recommended ingredient for proper efficacy is retinol.

- Skin Reactions and Caution for Using

Using retinol may cause skin reactions that have not been easily seen in other ingredients. Depending on the skin type, skin reactions such as stinging, burning, skin peeling, and redness may occur. These skin reactions are phenomena that can occur when retinol works effectively on the skin. This is not a phenomenon that occurs in all skin and can be disappeared after enough period of adaptation. It is recommended that you pay more attention to your skin condition while using retinol.

However, in the case of pregnant and lactating women, it may cause side effects to the fetus, so please avoid using it during that period.

COSRX Retinol Product Recommendation

COSRX has two retinol creams, both derm-skincare formulas that compound retinol in high concentration. In Jordan you will find them as a cream with 0.1% retinol and a cream with 0.3% retinol.

Because the retinol concentrations are different, you can choose the product depending on the effect and after-feel that you want.

If you are new to retinol or are a little worried about using retinol, try 「The Retinol 0.1 Cream」.

The Retinol 0.1 Cream

The Retinol 0.3 Cream

Tips to adapt to Retinol

It is important that using a product that contains a high concentration of retinol is necessary to go through a guided adaptation process.

During the adaptation period, you may have skin reactions temporarily such as tingling, redness, peeling, etc. or there is no skin reaction.

Even if there is no skin reaction to the first use, it is recommended to use it according to the guidance for use at the beginning as you may have the adaptation reaction late. If the retinol-sensitive reaction continues after the adaptation period, it is better to gradually increase the amount of use and cycle of use by considering the skin condition rather than increasing it at once.

If your skin is sensitive to reaction, it may be helpful to use 「The 6 Peptide Skin Booster Serum」 or 「The Hyaluronic Acid 3 Serum」 before using retinol.

The 6 Peptide Skin Booster Serum The Hyaluronic Acid 3 Serum

Written by the COSRX R&D Center. This guide is for general skincare education and is not medical advice. If you have a skin condition, are pregnant or breastfeeding, please consult a dermatologist.

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