I've used a whole bunch of niacinamide serums, from both korean and non-korean brands, but I found myself coming back to this one. No other product removes the dark spots my acne leaves as effectively as this one. The marks that usually takes more than a week to pale disappears within days when I use this serum.  It's easily absorbed and I also find it very moisturizing and soothing... probably because of squalane and different natural extracts in the ingredients. Anyway, my skin just loves it, so unless I get rid of my acne I think I'll just keep buying and using it.