Is 13% vitamin C strong enough to fade dark spots?

13% is a moderate strength that many people use daily. Expect gradual fading over several weeks rather than overnight results.

Can I use this serum every day?

Yes, most users apply it once daily in the morning. Start every other day if your skin is sensitive, and use sunscreen during the day.

Two bottles of the same 13% vitamin C serum. There is no separate formula or size difference between them.

The brand lists dry and all skin types. Layer a moisturizer over it, since vitamin C serums alone are not very hydrating.

The best new price was $14.24 at eBay as of November 5, 2026. Check the price history before buying, since serum prices move with sales.

COSRX markets the line as gentle and cruelty-free, but check the full ingredient list on the bottle if you avoid fragrance.

At eBay, for $14.24, 28% under what the other stores charge, as of our latest check.

Rated 4.6 out of 5 from 337 ratings.

14 stores we checked sell it, including eBay, Vitacost.com, iHerb, Walmart, Nordstrom.

4.6

$14.24at eBayObserved at 11:42 AM

28% under what the other stores charge

Compared across 6 stores. Prices are checked against each store and labelled with when.