COSRX Vitamin C 23 Serum: a Guru Score of 69% from 2 experts

What the gurus are saying.

Every take we've logged from this product's reviews across YouTube. Click any row to watch the moment they said it.

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~Mixed

"This is going to be one of the strongest vitamin C's that I talk about today. One thing I really respect about this brand and how they handled the product, aside from it being very affordable, is the fact that they tell consumers that you should go through this product within two months of opening it. That is the reality of these less stable vitamin C formulations. This product has 23% [L-ascorbic] acid, plus other pigmentation fighting ingredients like licorice root extract, niacinamide, and glutathione. And to me, that means if you can tolerate this product, you're probably going to see enhanced results when it comes to fighting hyperpigmentation because you have all those great brightening ingredients in there in addition to the vitamin C. However, those stronger concentrations can be more irritating for some skin types. So, it is definitely something to look out for. This is sort of a thin, watery serum with a slightly oily texture. I found that it applied quite evenly."

AliceintheRabbitHole

59k subs

~Mixed

"The COSRX vitamin C23 serum uses 23 percent ascorbic acid. With a higher percentage like this compared to 15 percent, you might not necessarily see more of the anti-aging benefits, you might get the same amount of benefits but possibly more of the irritation that can come with ascorbic acid. This might be a great product, but I have a bit more of a sensitive skin type, so I did not finish my bottle of this. I don't personally use ascorbic acid because it's a little harsh on me. If you are a bit more tough in your skin you might really like this, it has a great price, 25 dollars, 12.50 in this sale, just make sure you refrigerate it as soon as you open it."

All 2 takes from AliceintheRabbitHole

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"The COSRX vitamin C23 serum uses 23 percent ascorbic acid. With a higher percentage like this compared to 15 percent, you might not necessarily see more of the anti-aging benefits, you might get the same amount of benefits but possibly more of the irritation that can come with ascorbic acid. This might be a great product, but I have a bit more of a sensitive skin type, so I did not finish my bottle of this. I don't personally use ascorbic acid because it's a little harsh on me. If you are a bit more tough in your skin you might really like this, it has a great price, 25 dollars, 12.50 in this sale, just make sure you refrigerate it as soon as you open it."

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"This is the vitamin C 23 and I like it a lot more than I thought I would. When I first got it I wasn't very impressed, it already looked a little yellow out of the packaging. It's a pure ascorbic acid product, and yellow is still okay, it just means it's probably going to turn orange or brown eventually, which is why COSRX recommends storing it in the fridge. At 23 percent l-ascorbic acid, which is above the levels studied in research, I was worried it would sting, but they included a lot of calming ingredients and it actually doesn't sting my sensitive skin. That said, I'm a little bummed it's only 20 milliliters, it doesn't look like it in the bottle they put it in. I'll finish it as long as it doesn't turn brown or orange, but it's not my absolute favorite vitamin C."

What the evidence says.

Independent of what the gurus think, this is what the published research supports about the main active ingredients here.

Frequently asked.

Is COSRX Vitamin C 23 Serum worth it?

The gurus mostly approve it, but with enough reservations to keep it in the middle at a Guru Score of 69%.

What is COSRX Vitamin C 23 Serum's Guru Score?

COSRX Vitamin C 23 Serum holds a Guru Score of 69%. That is our read on how warmly the experts talk about it, based on the verdicts of 2 expert reviewers we have collected.