Serums and moisturizers go together like peanut butter and jelly, like cookies and milk, like pizza and ranch dressing. (I can’t be the only one who’s into that last combo, right?) Whatever your pizza dipping preferences are, my point stands: The best serum and moisturizer combinations prove the two are better together than they are apart — really, they were made to complement each other.
Serum should be applied first, since products in this category are usually water-based and lightweight, and contain active ingredients targeted towards a particular skin issue. For example, vitamin C brightens and improves hyperpigmentation, while hyaluronic acid, which can hold up to 1,000 times its weight in water, adds hydration. The low molecular weight of a serum means these ingredients should easily penetrate the top layer of skin, sink deep into pores, and get to work. But in order to do its job effectively, serum needs a teammate: moisturizer. Moisturizers are heavier than serums, and typically feature emollients (like beeswax and shea butter) or occlusives (like silicones and mineral oil) to help “lock in” moisture — and lock in the actives of the underlying serum. To continue the pizza metaphor, think of serum as the sauce and moisturizer as the cheese. Without a layer of cheese (moisturizer) baked on top, the sauce (serum) would slide right off.
You can’t just apply any serum-moisturizer combo and expect delicious results, though. Ahead, derms break down the exact ingredients to look for — and their favorite product duos — based on your skin type.