Niacinamide

It usually varies for each person depending on your skin type! As someone who has dry skin, this usually dries my skin out so I have to avoid it. But I know people with more resilient skin who can manage it!

Yes, it's a great combo for brightening the skin. 😊 If both serums have high percentages, be sure to patch test first 😉

Yes you can, but if you use high concentrations of both you might experience some irritation.

Yup! Niacinamide plays very well with other ingredients.