The collagen serum is fantastic. I use it before using the tool and it works AMAZINGLY - almost out!!! Also the masks (same brand) are great and stay on while sleeping roughly! The merit serum is great for mornings/before makeup for a nice natural glow! I have sensitive skin and all of these products have done wonders for me - Especially the tool which sculpts my face in seconds! LTKstyletip LTKbeauty LTKfindsunder50