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COSRX Derm Serums Review

COSRX is a Korean skincare brand known for its simple but effective products. COSRX’s new Derm Serums that launched under their THE RX line are highly concentrated serums that are researched-backed and designed to target specific skin concerns.

Since I am a fan of COSRX products (their essence is one of my favorite soothing products), I couldn’t wait to try them, so I ordered them all.

COSRX Derm Serums Review: The Hyaluronic Acid 3, The Vitamin C 23, The Retinol 0.5 and The Niacinamide 15.

In this COSRX Derm Serums Review, I discuss my experience with a niacinamide serum, hyaluronic acid serum, vitamin C serum, retinol serum, and retinol cream from COSRX’s The RX line.

This post contains affiliate links, and any purchases made through these links will result in a commission for me at no extra cost to you. Please read my Disclosure for additional information.

COSRX Derm Serums Review

When COSRX Derm Serums launched, I was very excited to see these Korean skincare products formulated with retinol and other potent ingredients that you don’t usually see in higher concentrations in Korean skincare.

The serums are affordably priced and formulated with potent active ingredients. Another plus is that all Derm Serums are fragrance-free, and all COSRX products are cruelty-free.

SPOILER: I must admit that I’m very impressed with the non-nonsense formulas. Continue reading to hear about my experience with each product.

COSRX The Vitamin C 23 Serum

COSRX The Vitamin C 23 Serum

COSRX The Vitamin C 23 Serum is a highly concentrated vitamin C serum formulated to brighten your skin, fade dark spots and acne scars, hydrate your skin, and firm your complexion.

The serum contains 23% pure vitamin C, also known as ascorbic acid, which has three main benefits for the skin:

  1. Vitamin C brightens the skin by inhibiting melanin production.
  2. Vitamin C offers antioxidant benefits.
  3. Vitamin C promotes collagen production for smoother, firmer, more youthful-looking skin.

COSRX The Vitamin C 23 Serum Key Ingredients

  • Ascorbic Acid: A 23% concentration of pure vitamin C offers multiple benefits for the skin, including smoothing the look of wrinkles and fine lines, antioxidant protection, and brightening dullness and uneven skin tone.
  • Tocotrienol: Known as “super vitamin E”, this compound offers up to 50x greater antioxidizing effect than tocopherol (vitamin E).
  • Squalane: A natural emollient found naturally in the sebum of skin as squalene, squalane is a stable, non-irritating oily liquid that helps keep the skin moisturized.
  • Panthenol: A form of vitamin B5, panthenol helps to hydrate and soothe the skin.
  • Ethyl Ascorbyl Ether: This etherified form of vitamin C is more stable in formulations than ascorbic acid and is less likely to cause irritation.
  • Caffeine: Caffeine has antioxidant and anti-inflammatory benefits for the skin.
  • Sodium Hyaluronate: A form of hyaluronic acid, sodium hyaluronate is a moisture-binding ingredient that helps to keep the skin hydrated.
  • Glutathione: An antioxidant that helps to protect the skin from environmental stressors.
  • Adenosine: A molecule that has anti-inflammatory and skin barrier repair benefits. It may even help support collagen production for firmer skin.
  • Acetyl Glucosamine: An amino acid sugar that helps brighten the skin.
  • Allantoin: An anti-inflammatory ingredient that helps soothe the skin
  • Tocopherol: The pure form of vitamin E, tocopherol is an antioxidant that helps to protect the skin from environmental stressors.
  • Arginine: An amino acid that helps hydrate the skin.
  • Niacinamide: A form of vitamin B3, niacinamide has multiple benefits for the skin, including brightening dullness, evening out the skin tone, and reducing the appearance of fine lines and wrinkles.
  • Helianthus Annuus (Sunflower) Seed Oil: A non-comedogenic, light oil rich in linoleic acid (a moisturizing fatty acid) and antioxidant vitamin E.
  • Glycyrrhiza Glabra (Licorice) Root Extract: A plant extract with brightening and anti-inflammatory benefits for the skin.
  • Carthamus Tinctorius (Safflower) Seed Oil: This oil is a very lightweight and is easily absorbed into the skin. It is rich in linoleic acid, which helps to keep the skin moisturized. It also has anti-inflammatory properties, which make it ideal for irritated skin.
  • Camellia Japonica Seed Oil: An antioxidant-rich oil rich in vitamins and nourishing fatty acids.
  • Daucus Carota Sativa (Carrot) Root Extract: This plant extract is rich in beta-carotene, a potent antioxidant that helps protect the skin from environmental stressors.

As you can see from the list above, this Korean vitamin C serum is filled with good-for-your-skin ingredients.

The real test for me was how my skin would respond to such a high concentration of vitamin C. I am rather shocked that I experienced no irritation, which never happens when I use a vitamin C serum with over a 15% vitamin C concentration.

COSRX The Vitamin C 23 Serum open with dropper.

The lightweight serum has a watery texture that absorbs quickly into the skin. I like to apply it after toning my skin and before applying moisturizer.

It does have that tell-tale hot dog scent which comes along with water-based ascorbic acid serums that I’ve used in the past, but the scent dissipates pretty quickly.

I like to use vitamin C serums during the day for their antioxidant protection. When I apply the serum under makeup, it dries quickly and works seamlessly without being greasy or sticky on my skin.

I haven’t noticed brighter skin, but I use vitamin C for its antioxidant protection from free radicals.

This is a very impressive vitamin C serum at a very affordable price. I will continue to use this serum for its multiple benefits and comfortable wear.

COSRX The Niacinamide 15 Serum

COSRX The Niacinamide 15 Serum

COSRX The Niacinamide 15 Serum contains a high 15% concentration of niacinamide for what COSRX calls “total acne control.”

It combines niacinamide with oil-controlling actives that help reduce sebum production and balance your complexion while targeting whiteheads and blackheads.

Ideal for combination, oily, and acne-prone skin, this serum helps to soothe breakouts and reduce the look of enlarged, congested pores.

It gently exfoliates away dead skin cells, helping to brighten dull skin. It also smoothes rough, uneven skin texture.

COSRX The Niacinamide 15 Serum Key Ingredients

  • Niacinamide: Also known as vitamin B3, niacinamide is an all-star active that offers many skin benefits, especially for acne-prone or oily skin. It helps regulate sebum production, brighten the skin tone and improve the appearance of enlarged pores. It also has anti-aging benefits in that it helps to increase collagen production and smooth the look of wrinkles and fine lines. Niacinamide also supports a healthy skin barrier and helps reduce inflammation and redness associated with acne breakouts.
  • Acetyl Glucosamine: This natural moisturizing factor helps keep the skin hydrated. It also fades dark spots and hyperpigmentation.
  • Zinc PCA: This ingredient helps control sebum production, treat breakouts, and reduce inflammation.
  • Allantoin: Derived from the comfrey plant, allantoin is a skin-soothing agent that helps calm and soothe irritated skin.

The serum has a thin consistency and isn’t sticky or greasy on my skin. Even though this is a higher concentration of niacinamide, this lightweight serum did not irritate my skin or cause any redness.

COSRX The Niacinamide 15 Serum open with dropper.

It does a great job of keeping oil at bay throughout the day, especially in my t-zone. I also like to use this in the evening paired with retinoids like retinol since niacinamide can help reduce irritation and strengthen your skin barrier.

I think this would be ideal for oily skin and enlarged pores since it contains a higher concentration of niacinamide.

Overall, I’m really happy with this Korean serum and would recommend it to anyone looking for a lightweight niacinamide serum to help with oil control.

COSRX The Hyaluronic Acid 3 Serum

COSRX The Hyaluronic Acid 3 Serum

COSRX The Hyaluronic Acid 3 Serum is a serum formulated with a high 3% concentration of hyaluronic acid.

The serum is formulated to not only hydrate and plump the skin but also soothe and strengthen the skin’s natural moisture barrier.

Ideal for dehydrated, dry skin types, this serum will also help with loss of firmness and uneven skin texture.

COSRX The Hyaluronic Acid 3 Serum Key Ingredients

  • Sodium Hyaluronate (3%): This form of hyaluronic acid is highly effective in retaining moisture in the skin and helps maintain skin structure and balance.
  • Betaine: A natural amino acid that helps to strengthen the skin’s barrier
  • Sodium PCA: A natural moisturizing agent that helps to keep the skin hydrated
  • Sodium Lactate: A moisturizer and humectant that helps balance the pH of the formula.
  • PCA: A Natural Moisturizing Factor in the skin that helps skin retain moisture.
  • Serine, Alanine, Glycine, Threonine, Arginine, Proline: Amino acids that help hydrate, moisturize, and repair the skin.
  • Ceramide NP: A type of ceramide that helps to fortify the skin’s natural barrier
  • Cholesterol: A type of lipid that helps to fortify the skin’s natural barrier
  • Phytosphingosine: A lipid found naturally in our skin that has antimicrobial and skin protective benefits
  • Tocopherol: A form of Vitamin E that has antioxidant and emollient properties.

This is the highest concentration hyaluronic acid serum that I’ve tried. I don’t notice a huge difference in moisture levels of my skin compared to a 2% hyaluronic acid serum, but I do like the lightweight texture, which easily allows it to be layered with other serums.

The lightweight serum is thin and easily absorbs into my skin without feeling sticky or greasy. Some hyaluronic acid serums leave my skin feeling tacky and sticky, but this one sinks right in. My skin feels hydrated and plump after using it.

I like to use this serum both in the morning and at night, and often layer it under my sunscreen in the morning and my moisturizer at night. It’s also light enough to use under makeup.

This is a winner for me thanks to the light texture, high HA concentration, and hydration-boosting benefits.

If you struggle with dehydrated or dry skin, this serum will add a lightweight layer of non-sticky hydration that will boost moisture levels in your skin.

COSRX The Retinol 0.5 Oil

COSRX The Retinol 0.5 Oil

COSRX The Retinol 0.5 Oil is COSRX’s higher-strength retinol product. It contains 0.5% pure retinol without any purified water or retinol derivatives.

This base of the serum is a 91% concentration of squalane. Squalane is a lightweight moisturizer that supports a healthy skin barrier while calming inflammation.

The retinol oil is formulated to improve the look of wrinkles and fine lines and improve skin texture, elasticity, and radiance.

The ingredient list is short and contains only ten total ingredients.

COSRX The Retinol 0.5 Oil Key Ingredients

  • Squalane: Squalane, a saturated hydrocarbon, is naturally found in the skin in the form of squalene. It has exceptional emollient properties that help to soften and condition the skin without clogging pores. Squalane is non-irritating, non-comedogenic, and suitable for all skin types.
  • Glycine Soja (Soybean) Oil: Glycine soja oil is a natural oil derived from soybeans. It is rich in fatty acids, which help nourish and moisturize the skin.
  • Retinol (0.5%): Retinol is a form of Vitamin A that increases cell turnover and helps reduce wrinkles and fine lines. It also helps to improve skin tone and texture.
  • Tocotrienols: Tocotrienols are a type of vitamin E that appear to be more effective than traditional vitamin E in protecting the skin against free radical damage, which can result in premature skin aging, including wrinkles and fine lines.
  • Tocopherol: The pure form of Vitamin E, tocopherol is an antioxidant that scavenges free radicals and helps to protect the skin from damage.

This retinol oil is best suited for those who have used retinol before and have acclimated their skin to retinol (i.e., intermediate retinol users). I consider myself to be only an intermediate retinol user because, while I can use retinol at concentrations above 0.1% without irritation, stronger formulas tend to cause irritation.

COSRX The Retinol 0.5 Oil open with dropper.

This retinol oil is lightweight and non-greasy on my skin. I really appreciate the squalane base that moisturizes your skin because retinol tends to dry out my skin quickly.

I have been using the serum every other night and have not experienced any drying, redness, or irritation.

Overall, I am very pleased with how my skin looks and feels after using this product for a few weeks. My skin looks smoother and more even-toned.

If you deal with the loss of firmness, dullness, wrinkles, and fine lines, this gentle retinol oil serum could be a great choice for you.

COSRX The Retinol 0.1 Cream

COSRX The Retinol 0.1 Cream

If you are starting to deal with the signs of aging like wrinkles and fine lines, COSRX The Retinol 0.1 Cream contains a low 0.1% retinol concentration, perfect for beginners.

Retinol is the gold standard over-the-counter active ingredient for anti-aging benefits.

The retinol cream is formulated with 0.1% pure retinol for low irritation. The cream also helps to improve skin elasticity and texture while fading acne scars and preventing future acne and breakouts.

It’s ideal for loss of firmness, skin dullness, and roughness.

COSRX The Retinol 0.1 Cream Key Ingredients

  • Pure retinol (Vitamin A) 0.1%: Retinol is an anti-aging powerhouse that improves the appearance of fine lines and wrinkles, brightens skin tone, and promotes collagen production.
  • Shea Butter: This antioxidant-rich ingredient helps to protect the skin from environmental stressors while also providing nourishing moisture.
  • Panthenol: A form of Vitamin B5, Panthenol works to soothe and replenish the skin.
  • Adenosine: Adenosine is a yeast-derived ingredient that has anti-wrinkle and skin-restoring properties.
  • Tocotrienol (Super Vitamin E): A more potent form of Vitamin E, Tocotrienol works to nourish and protect the skin.
  • Tocopherol: The pure form of Vitamin E, this natural antioxidant that fights free radical skin damage.
  • Daucus Carota Sativa (Carrot) Root Extract: Packed with beta-carotene and vitamins A, C, and K, this extract improves the skin’s elasticity while providing antioxidant benefits.
  • Allantoin: This ingredient is derived from the comfrey plant and helps to soothe and calm the skin.
  • Helianthus Annuus (Sunflower) Seed Oil: A non-comedogenic oil rich in vitamin E, sunflower seed oil helps hydrate and protect the skin.

This lightweight cream is unscented and absorbs quickly into the skin without leaving any greasy residue. It feels very moisturizing on my skin, which is a plus since retinol can sometimes cause dryness.

While this is a low amount of retinol, it is the perfect starter retinoid, as it did not irritate my somewhat sensitive skin at all. I did not experience any dryness, redness, or flaking, which is often associated with retinol use.

I’ve been using this retinol cream for a few weeks now and have seen an improvement in the overall texture of my skin. My skin feels softer and looks more radiant.

While I don’t expect to see huge changes in my skin with this low retinol percentage, it’s a great option if you are a beginner retinol user or want to use it as a preventative measure against future signs of aging, like wrinkles and fine lines.

COSRX The Derm Serums

I think COSRX’s line of derm serums is an excellent option for products that contain active ingredients like hyaluronic acid, niacinamide, retinol, and vitamin C.

My favorites? COSRX The Vitamin C 23 Serum and COSRX The Niacinamide 15 Serum for their high concentrations and minimally irritating formulas that offer real results.

Thanks for reading, and until next time, here’s to your good skin health!