Putting aside the claims, hype, and misleading information you may have heard, the only real difference between a daytime and nighttime moisturizer is that the daytime version should contain a well-formulated sunscreen. A popular myth told repeatedly by cosmetics salespeople echoes the notion that skin is doing some kind of special repairing at night that it isn’t doing during the day. Even if that were true, and there is no research indicating it is, exactly what those ingredients are supposed to be has never been identified in any medical or scientific journal.
Skin is struggling to heal and repair itself 24 hours a day. It is not doing anything different at night than it is doing the day except taking a rest from the assault of sun exposure. And therein lies the only difference between a daytime and nighttime moisturizer. For daytime wear, unless your foundation contains an effective sunscreen, it is essential that your moisturizer features a well-formulated, broad-spectrum sunscreen rated SPF 15 or higher. Well-formulated means it must contains the UVA-protecting ingredients of titanium dioxide, zinc oxide, avobenzone (also called butyl methoxydibenzoylmethane), Tinosorb or ecamsule (Mexoryl). As for moisturizing in general, your skin needs all the state-of-the-art ingredients I described in this chapter—antioxidants, skin-identical ingredients, and cellcommunicating ingredients—regardless of the time of day.