Apply this serum in the evening on clean, dry skin, after your lotion/toner. Start 2 to 3 times a week (the 1.0% is strong), then increase the frequency if your skin tolerates it. Use 1 to 2 pumps for the entire face, avoiding the eye and lip areas. Let it absorb, then finish with a soothing moisturizer. Essential: high sun protection every morning throughout the entire period of use.