Skincare routines with:
Kiehl's Powerful-Strength Dark Circle Reducing Vitamin C Eye Serum

Use every day, as many times as needed. For most people, it's best to use a moisturizer twice per day. In the morning, apply it before your sunscreen (or skip the moisturizer in the morning if your sunscreen feels hydrating enough). In the evening, a moisturizer is usually the last step of a routine.

Start slowly with this product: it can be irritating, but your skin can adjust to it with time. It is best to start using this product only a few times a week or every other day for the first few weeks. Mild dryness is normal when starting using a retinoid. Once your skin is able to tolerate the product well, you can slowly increase the frequency of use to every day. Make sure to apply a moisturizer regularly when using this product. Apply this product on clean skin, before a moisturizer. Most people prefer using this product at night, but it can be used in the morning as well (once per day in total).