At first I was upset because the product contains alcohol which is actually needed for vitamin c stabilization, and because I have read such a huge vitamin c concentration of 20 % is only for skilled users, but I decided to try it and I am excited with the result.
I used it after a thick toner, I blended it with an emulsion and then I covered everything with the night mask.
In the morning my skin had an even tone and looked so healthy that I might not use any of the skincare.
I am a bit shocked because I did not have such results even after 2 years thoughtful Korean routine.
I think this serum is more for the oily and combo skin, and it has slightly drying result, that's why night mask is really needed.

I will go on with using it twice a week, and my only concern now is that such kind of serum can not be kept long time, so I hope it will last safe till I finish it.