I have used this product for 3 weeks now. The serum feels like water slipping through your fingers. It is very hard to use a small amount without losing half of the product running down your drain. My skin tightens after application and it does not feel nice using it. I apply my Kiehl's moisturiser after the serum. I haven't noticed any difference in my skin and haven't seen any improvements since I started using the serum. I would not recommend nor would I repurchase. I doubt there is hyaluronic acid in this product considering the texture of the serum.