COSRX The Vitamin C 23 Serum for sensitive skin

How to apply

Questions and answers

What the research says

• A topical serum containing vitamin C, vitamin E, and raspberry leaf cell culture extract improved skin color, elasticity, radiance, smoothness, scaliness, and wrinkles compared to the untreated contralateral side in fifty female volunteers.

  Journal of Cosmetic Dermatology, 2020

• Squalane at 0.005-0.015% counteracts UVA-induced oxidative stress, inflammation, and collagen metabolism inhibition while stimulating fibroblast migration in human dermal fibroblasts.

  Molecules, 2025

• Concurrent treatment with 3-O-ethyl ascorbic acid and cannabigerol in UVB-irradiated human keratinocytes prevents membrane structure alterations, promotes cell survival, enhances antioxidant enzyme activity and GSH- and Trx-dependent systems, reduces lipid and protein oxidative modifications, and exerts anti-inflammatory effects.

  Free Radical Biology & Medicine, 2025

• Topical application of 5% vitamin C cream significantly improved global clinical scores, increased skin microrelief density, and induced elastic tissue repair in photoaged skin compared to excipient control in healthy female volunteers.

  Experimental Dermatology, 2003

• Ascorbic acid 2-glucoside gel significantly reduced gingival melanin pigmentation after 4 weeks compared to placebo in 73 subjects with symmetric pigmentation.

  Journal of Periodontology, 2009

• Topical application of VC-IP cream twice daily for 8 weeks reduces periorbital wrinkles in female subjects compared to a placebo cream.

  Journal of Cosmetic Dermatology, 2022

• Topical application of 0.1% hyaluronic acid formulations of different molecular weights led to significant improvements in skin hydration and elasticity, with low-molecular-weight formulations also significantly reducing wrinkle depth in seventy-six female subjects compared to a vehicle control.

  Journal of Drugs in Dermatology, 2011

• Topical application of hyaluronic acid in conjunction with free gingival graft significantly reduced donor site postoperative pain until day 7 compared to normal saline, with no significant differences in graft dimensions or patient satisfaction.

  Clinical Oral Investigations, 2022

• Treatment with a hyaluronic acid-containing mouth rinse or topical gel led to significant lesion reduction, pain relief, and normalization of lesion color in adult patients with minor recurrent aphthous stomatitis, with the gel formulation showing an earlier healing onset at 3 days.

  BMC Oral Health, 2019

• Topical application of an antioxidant serum containing 15% ascorbic acid, 0.5% ferulic acid, and 1% tocopherol prevented particulate matter-induced degradation of extracellular matrix components, inflammation, and oxidative stress in the skin of 15 female volunteers compared to untreated controls.

  Journal of Cosmetic Dermatology, 2025

• Dermatological products containing d-alpha tocopheryl acetate showed non-comedogenic potential with less than a 50% increase in microcomedones in 12 healthy male subjects compared to octyl palmitate.

  Contemporary Clinical Trials Communications, 2021

• Topical application of an antioxidant mix containing 15% ascorbic acid, 0.5% ferulic acid, and 1% tocopherol prevented PM and UV-induced skin barrier perturbation, lipid peroxidation, inflammatory markers, MMP9 activation, and Type I collagen loss in 15 healthy females compared to untreated exposed skin.

  Journal of Cosmetic Dermatology, 2024

• Plant-derived squalane protected human dermal fibroblasts against UVA-induced damage by counteracting ROS formation, suppressing apoptosis-related proteins p53, caspase-3, caspase-9, and PARP, and restoring the pro-survival p-Akt/mTOR pathway.

  Antioxidants, 2025

• Topical post-laser application of human adipocyte-derived mesenchymal stem cell media combined with niacinamide significantly improved wrinkle index, melanin index, patient satisfaction, and investigator esthetic improvement scores compared to vehicle cream in patients with aging skin.

  Journal of Cosmetic Dermatology, 2021

• Topical nicotinamide prevented solar-simulated UV-induced immunosuppression in healthy volunteers, and men experienced immunosuppression at solar-simulated UV doses three times lower than those required for women.

  The Journal of Investigative Dermatology, 2008

• Topical 5% niacinamide applied twice daily for 12 weeks reduced fine lines and wrinkles, hyperpigmented spots, red blotchiness, and skin sallowness, and improved skin elasticity compared to vehicle control in 50 female white subjects with facial photoaging.

  Dermatologic Surgery, 2005

Ingredients

Water, Ascorbic Acid, Propanediol, Dimethicone, Tromethamine, Panthenol, 3-O-Ethyl Ascorbic Acid, Squalane, Caffeine, Sodium Chloride, Sodium Hyaluronate, Sodium Sulfite, Disodium Edta, Glutathione, Adenosine, Acetyl Glucosamine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Tocotrienols, Tocopherol, Palm Oil, Butylene Glycol, Arginine, Niacinamide, Pentylene Glycol, Alcohol Denat, Helianthus Annuus Seed Oil Sunflower Seed Oil, Glycyrrhiza Glabra Root Extract Licorice Root Extract, Methyl Trimethicone, Carthamus Tinctorius Seed Oil, Camellia Japonica Seed Oil, Daucus Carota Sativa Root Extract Carrot Root Extract, Beta-Carotene

Behind this fit score

Lovi calculates every fit score from the full ingredient list with brand-independent rules our dermatologists and cosmetic chemists build and review, and personalizes every pick with AI trained on the real results of millions of users. Lovi trains its fit score models on a proprietary dataset built from more than 10,000 expert-labeled products and more than 100,000 simulated examples, following an internally consistent methodology presented at Cosmoprof, AMWC, and Skin of Color Update.