Review (4/5): Generous size, not sure about concentration
These serums feel good on my skin and I have also been mixing them with my moisturizer. I’m not sure about the concentration of their active ingredients, and it does not say anything specific on the box or the bottle. I know that I have a different vitamin C serum that consistently creates a warming sensation on my skin, but this serum does not do that so it must be below 12%.