I just added this product to my routine (right now I do 1 day of this, 1 day off, then exfoliate, then 1 day off from treatments). At first, my skin was very red, but I also never used retinol before. I make sure my skin is dry before using it now and I also use a very tiny amount so my skin can get used to the retinol. Otherwise I like it, though, it seems like a good low concentration for retinol.