The ordinary niacinamide 10% + zinc 1%

May the percentage too high for your skin. I often get those feeling too everytime I'm using really high percentage of active

Did you have a patch test done before using it? Also, the concentration is high. After a successful patch test, I suggest you use this product in small quantities. I didn't have a good experience with it in the beginning. When my skin barrier was restored, I began using only a pea-sized drop for my entire face. That helped!

i threw mine in the trash can. it is such a poorly formulated serum. it gave me itchy bumps and huge cystic acne! it pills! it doesn't layer up with other skin care products.

Is this your first time using niacinamide? I think the percentage is too high. Maybe you can try lower percentage for the first time.....

if this is the first time you use niacinamide serum, you can try from lower percentage of niacinamide because the high percentage of niacinamide can cause irritation or breakouts