This serum was my favourite of the three Kiehl's serums which I tested for the 28-day #ChangeYourSkin Challenge. I saw results from this within the first few days of using it. I also loved the pump dispenser which makes it easy to use and keeps the serum airtight and hygienic. This serum is formulated to suit all skin types. It is light and watery on application (with little to no scent) and absorbs quickly without leaving any greasiness on the skin.

What this serum does best is fight dehydration. Even though my skin was combination to oily when I started using it, it was also very dehydrated. The first week I used it I did experience a slight stinging but this went away over time. My skin has felt hydrated and plumped up, my fine lines around my eyes are much less visible and my skin texture is smoother and softer. I also feel that I need far less moisturiser after applying this serum, and don't get any dry patches during the day even when wearing a very matte makeup.

There was nothing about this serum that I didn't love, so I give it five stars for effectiveness and quality. And I would gladly repurchase it when it runs out. The price isn't in the same range as affordable drugstore brands, but it is in line with serums from many other department store brands, and I think it is good value for money.