For myself I try to buy chemical free products. You only need to only apply this very sparingly. I washed my face in the morning and at night, applied the serum, let it dry and then applied my moisturizer. There are good skin care guides on the internet if you need some tips and to learn how to properly use this. Please keep in mind these products typically expire 12 months after opening. The serum is a clinical strength 20% vitamin C serum with hyaluronic acid and Vitamin E, 1oz, organic, vegan, made in the USA, FDA facility registered, never tested on animals, does not contain any animal product, paraben-free, safe for even the most sensitive skin sulfates and it is safe for all skin types. I had no irritation from using this product on my combination skin. It has a slight scent to it. It is a thin consistency but it does not leave your skin sticky or with a film. I like the bottle that it comes in to make it easy to dispense from the dropper and use. I would definitely purchase again in the future.