Reviews about Face Serum

I cannot call this a serum because, in my understanding, a serum is a combination of active ingredients for maximum absorption by the skin. The scent is like there is a fragrance added, but it could also be the smell of some oils (very strong).
For my face, I only need a drop the size of a pea (on damp skin, on dry skin it tightens the skin and feels "heavy").
It causes slight redness. I try not to leave this serum on my face for too long (up to 30 minutes), I use it for self-massage and as an oil mask.