COSRX

The Vitamin C 23 Serum

397 Reviews

• toto222

  Jun 24, 2025 (UTC)
  Combination Skin

  Review under verification

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  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  This is a product I always use. It's not too harsh on the skin and the price is reasonable, so I stock up on it.

  Cons

  Sometimes I receive products that have already turned yellow, which makes it feel like a gamble.

  Tip

  The reviewer appreciates the gentle nature and affordability of the product, leading them to buy in bulk. However, they express disappointment about occasionally receiving discolored items, suggesting inconsistent quality control.

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• 밤톨그녀

  Jun 20, 2025 (UTC)
  Oily Skin

  Review under verification

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  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  First off, the texture is quite fluid. When you shake the product and apply it to your cheeks with the dropper, it immediately starts to run. In my case, I had to use one hand to apply and the other to quickly spread it over my face. While it feels light and silky during application, it transforms into a more elastic texture as it absorbs into the skin. Once fully absorbed, your face feels incredibly smooth and soft. I was initially concerned about the 23% pure Vitamin C content, but surprisingly, there was no irritation except on areas with existing blemishes. Still, I'd recommend using it when your skin is in good condition. While the results aren't dramatically instant, I noticed subtle improvements in tightening slightly enlarged pores and a noticeably brighter complexion. I'm not sure yet about its effects on my main concerns - dark spots and blemishes - but overall, it's a decent product for its price point.

  Cons

  Due to oxidation, you need to store it in the refrigerator when not in use and use it up quickly. The scent might be divisive - I found it okay, but others might disagree. Also, be careful when applying moisturizer over this product, as they can mix and potentially stain your pillow while you sleep.

  Tip

  For best results, apply a face mask right after using this product.

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• 풍성한공작나비67239

  Jun 19, 2025 (UTC)
  Dry SkinSensitive SkinAcne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  "To be honest, I've never heard anyone say their skin got noticeably brighter until I used this!" I always thought Vitamin C serums were harsh, but COSRX's Pure Vitamin C 23 Serum surprised me with its gentle and smooth application. The texture is like a thin oil that flows like water, but once applied, it absorbs quickly with almost no stickiness. At first, I thought, "Isn't this too oily?" due to the oil layer, but after absorption, my skin felt firmer with a noticeable glow. I prefer lightweight basics with definite results, so I discovered this product while looking for a high-concentration Vitamin C. With 23% pure Vitamin C, it visibly brightened my dull complexion. I'm especially pleased to see a gradual fading of my recent sun spots and blemish marks. Recommended skin type? It worked particularly well for my sensitive, combination skin prone to blemishes. For those with sensitive skin, I suggest using it every other day at first to allow for an adjustment period. Thanks to its soothing ingredients, I didn't experience any tingling or redness. What I appreciated most was the inclusion of hydrating and calming ingredients like hyaluronic acid, allantoin, and niacinamide. This meant I could use a high-concentration vitamin serum without disrupting my skin's balance. And the ingredients are truly impressive... It contains Vitamin E (tocotrienol) to prevent oxidation, plus glutathione, caffeine, and squalane... It feels like a complete skin care serum!

  Cons

  Like most Vitamin C serums, storage can be a bit inconvenient. It needs refrigeration and should be used within two months of opening, which might be challenging if you tend to stockpile skincare products. There's also that distinctive vitamin scent... While you get used to it, at first you might think, "Is that a hot dog smell?" Although I experienced minimal irritation, depending on your skin type and condition, you might feel a slight burning sensation at first. For those with sensitive skin, I strongly recommend doing a patch test!

  Tip

  After cleansing and toning, I pat the Vitamin C serum into my skin and wait about 2 minutes. Then I finish with a moisturizer, and my skin feels incredibly firm! If you want to use it in the morning, sunscreen is an absolute must! While it gives you a glow, sun exposure can actually be counterproductive, so I strongly recommend pairing it with a physical sunscreen of at least SPF 50. Keeping it cool is a real treat. Storing it in the fridge not only cools your skin when you apply it in the morning but also leaves you feeling refreshed - it's a win-win!

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• 미오MIㅡO

  Jun 14, 2025 (UTC)
  수부지Sensitive SkinAcne Skinproduct.Atopy Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  I've been using this for about 3 weeks, and I love how lightly it applies. Many high-concentration vitamin products tend to be sticky, but this one goes on very smoothly with less irritation (though not completely irritation-free). It does feel a bit rich, but it's not overly sticky and leaves a soft, velvety finish. I've never experienced any tingling when applying it, and it hasn't caused any blemishes, making it great for daily use.

  Cons

  First off, the color is somewhat yellowish, and the texture is quite unique. When you drop it on your skin, it doesn't adhere at all - it rolls around like oil. Even when you try to rub it in, it feels as if your skin has become water-repellent, with droplets forming instead of absorbing immediately (maybe because my skin is dry?). It feels more rich than hydrating. I noticed something peculiar while using it... After applying this serum, if I try to layer on a soothing gel or hydrating ampoule, those products turn watery and just drip off like when you're washing your face. I was so shocked at first! I tried to use an aloe gel pack, but it just turned into liquid and started dripping. The same thing happens with sheet masks, though not as severely. They say vitamin products should be applied in the first step, but with this one, I think it might be better to apply it later in your routine. I hope this information is helpful for those using this product.

  Tip

  Since this product turns other hydrating products into water when layered, it might be better to apply it in a later step when using multiple ampoules, or make sure it's fully absorbed before applying other products.

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• 랄릴룰롤

  Jun 4, 2025 (UTC)
  Dry SkinSensitive SkinAcne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  After reading Hwahae reviews, I thought this might be a good product for my parents' age spots and blemishes, so I decided to give it a try. My mom has been using it consistently for her long-standing age spots and dark patches. I ended up trying it myself and was pleasantly surprised by the results, so I wanted to share my experience! First off, the texture is on the richer side, and since it's more concentrated, I thought it might be irritating. So I started with a small amount, but it turned out to be quite gentle, so I've been applying a moderate amount. However, I have combination dehydrated skin, and using this ampoule alone left my skin feeling a bit parched. So now I layer it over a hydrating toner or serum for better results. While I don't have age spots myself, I was curious to try it for my acne scars and blemishes. After using it for just five nights, I noticed my complexion looked clearer and brighter! I'm planning to purchase it again once I finish my current ampoule.

  Cons

  1. The most disappointing aspect is that using this ampoule alone can be quite drying, so I have to pair it with a hydrating serum. 2. It requires refrigeration, which can be a bit inconvenient to retrieve every time.

  Tip

  1. I've been using a hyaluronic acid-rich hydrating serum in place of toner before applying this product. This combination helps prevent any dryness. Also, since this product is packed with pure Vitamin C, it's crucial to focus on moisturizing. Make sure to apply plenty of moisturizer! 2. While it's fine to use in the morning followed by sunscreen, I personally prefer to apply it only at night as I'm not confident in my ability to maintain a consistent daytime routine.

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• js08

  May 12, 2025 (UTC)
  Combination SkinAcne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  I've been using this vitamin serum and it wasn't particularly irritating to my skin.

  Cons

  The brightening effect on my complexion is subtle. I think I'll need to use it consistently to see real results.

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• 드립마왕

  May 11, 2025 (UTC)
  Dry SkinSensitive SkinAcne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  I really appreciated that despite being a high-concentration vitamin C product, it didn't irritate my skin at all.

  Cons

  I can't really tell if it's effective. The smell is also unpleasant - it reminds me of canned tuna. Moreover, when I wake up after applying it, my face turns very yellow, and this yellow tint even transfers onto my pillow..

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• 겸미2222

  May 11, 2025 (UTC)
  Dry SkinSensitive Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  It's high in vitamin C, but I hardly felt any irritation! The hydration is great too.

  Cons

  It's not a lightweight formula, so those with oily skin might find it heavy at first. Since it's high in vitamin C, it can run when mixed with water! I mixed it with aloe gel and it was a disaster. Be careful!

  Tip

  There's a protective oil layer for the ingredients, so make sure to shake it well before use! I recommend shaking it up and down rather than side to side.

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• 나누기는행복

  Apr 13, 2025 (UTC)
  수부지Acne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  I tried COSRX as my first vitamin C serum! I bought a high-concentration product without knowing much, but fortunately, I didn't feel any irritation. Though it might have stung if my skin barrier was compromised. It seems to pair well with hyaluronic acid toners or serums. I recommend applying them together!

  Cons

  Great ingredients and excellent value for money! No blemishes, and there's absolutely nothing to complain about.

  Tip

  Please store it in the refrigerator. Also, I heard using it with a galvanic device can increase absorption!

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• 고고미09

  Apr 4, 2025 (UTC)
  수부지Sensitive SkinAcne Skin

  Review under verification

  The content is currently being reviewed by the Hwahae operations team, and the verification will be completed by the next business day (excluding weekends and holidays) from the date the review was written.

  OK

  Reviewed by The Hwahae Testers

  This review was written by The Hwahae Testers who received the product for free and evaluated it with a sense of representing Hwahae. The review is completely unbiased and honest, with no guidelines or restrictions. Reviews by The Hwahae Testers undergo the same strict verification process as regular reviews, and if they don't meet our standards, revisions will be requested.

  OK
  Pros

  The tricky storage is definitely a downside! Due to the nature of vitamin C products, it's prone to oxidation, so it must be refrigerated and the cap tightly closed after each use. When I first opened it, the serum was almost colorless, but over a month or two, I noticed it gradually darkening, which is a clear sign of oxidation. It's crucial to use it up relatively quickly for this reason.

  Cons

  보관이 까다롭다는 점! 비타민 C 제품 특성상 산화되기 쉬워서 꼭 냉장 보관해야 하고 사용 후 뚜껑을 꽉 닫아야 해요. 그리고 처음 개봉했을 땐 노란빛이 거의 없었는데 한두 달 지나면서 점점 진해지는 걸 보니 확실히 산화가 진행되긴 하더라고요. 그래서 빨리 쓰는 게 중요할 것 같아요.

  Tip

  Stock up when it's on sale for the best value!