I just use this in the morning. Think of it this way - After your cleanser, you want to go from the thinnest product to thickest on your face. You start with a toner to prep your skin for the serum and moisturizer to come, that's the thinnest product. Then you apply your serum, whatever it may be. Finally, you finish with the thickest product, your moisturizer (and oils if that applies). This particular product is a serum, and so as with any serum, you'll want to follow up with a moisturizer. Hope this helps!