The Vitamin C 13 Serum
SUMMARY OF REVIEWS
Creators keep circling back to COSRX The Vitamin C 13 Serum when they want something they can trust.
FULL REVIEWS
POSITIVE
- “This is the most potent skin brightening serum of this video because it contains 23% of L-ascorbic acid because it contains pure vitamin C”
- “It makes the formula little unstable that is it can go bad very easily if don't store it properly”
- “It is important that you do keep it in the fridge”
- “Once you have open it try to finish it up within six months time”
- “If your COSRX vitamin C serum has turned to darker yellow very golden yellow or very orangeish reddish color it means the serum has oxidized it is not safe to use”
- “COSRX vitamin C serum even though it contains 23% pure vitamin C the formulation is such that it's not gonna irritate your skin even if you use it daily”
- “I have used it daily in my nighttime skincare routine and it never caused a problem”
- “COSRX vitamin C serum works on all kind of pigmentation”
- Source: Reviewing 4 Popular Brightening Korean Serums for Dark Spots - Nov 21, 2025
MIXED / NEGATIVE
No negative reviews yet — creators have only had good things to say.
WHAT CREATORS SAY
- Consensus
- 4.5 / 5 from 1 creator reviewGrailPeople ratings based on creator reviews.
- ⚠ may not suit sensitive skin (1)
- ⚠ didn't help with redness / rosacea (1)
Product details
Details
- Type
- facial serum
- Finish
- —
- Shade
- —
- Key ingredients
- Ascorbic Acid, Sodium Hyaluronate, Squalane, Adenosine, Tocopherol, Allantoin, Niacinamide, Panthenol, Caffeine, Glutathione
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