Face serums are, without a doubt, the MVPs of any skincare routine. Still, despite their bona fide benefits, many of us are hazy on what they are, what they do, and even if they’re really necessary. To make it easy, we put together an expert-guided cheat sheet. So go ahead and save a spot on your shelf, in your cabinet, or on your vanity (if you’re fancy like that).
What exactly is a serum?
Serums are serious treatments “designed to deliver a high concentration of active ingredients to skin,” explains New York City dermatologist Joshua Zeichner, M.D. In other words, they’re the things that’ll ultimately produce the biggest changes in your complexion. “They can have a single active ingredient or multiple, and can range in consistency from a gel to a lotion to an oil,” he adds. Although other products in your routine, like oils and masks, also include actives, serums generally contain the largest amount.
So what do they do?
Serums can target everything from fine lines (like the Renew Repair Serum) to breakouts (like the Clear Repair Serum)—it all depends on the ingredient list. “A serum allows you to really personalize your skincare routine,” Zeichner says. Some ingredients to look out for are:
- Antioxidants, like vitamin C, green tea, and resveratrol, which protect skin from free radical damage, pollution, and the negative effects that come with them. “We know that pollution, whether it’s gaseous or particulate matter (tiny particles in the air that promote free radical damage when they deposit on skin), has been associated with premature aging and hyperpigmentation,” Zeichner explains. Think of antioxidants in a serum like a sunscreen for all sorts of environmental damage.
- Ceramides, AKA your skin barrier’s BFF and a must if your face is feeling sensitive or dry. “Ceramides are like the grout that fills in the cracks between skin tiles,” Zeichner says.
- Peptides, which Zeichner describes as “the messengers that tell skin to do a specific job.” In many cases, that job is to boost collagen, the structural protein that keeps skin looking youthful, bouncy, and smooth.
- Hyaluronic Acid, a powerful humectant that “acts like a sponge to bind with water, pulling hydration to the outer skin layer from deep within the skin or the environment.” The result: plumper, more supple skin.
- Willow Bark, a natural form of salicylic acid and a beta hydroxy acid that “removes excess oil and exfoliates dead cells from the surface of skin,” Zeichner explains. It promotes more radiant, brighter skin, less noticeable lines, and clearer pores.
When should you start using a serum?
Preventative skincare is ideal, but if you’ve started noticing lasting changes in your skin—maybe it’s that you look consistently tired or the lines on your forehead are a little more fixed—it’s time to invest in a serum. Zeichner recommends adding one to your skincare lineup around the age of 30: “That’s when skin cell turnover starts to slow down and hydration levels begin to decrease.”
What’s the difference between a serum and a face oil?
They come in similar packaging and some serums contain oils, making the differences between a serum and a face oil seem insignificant. But their goals are totally different: Consider face oil your moisturizer that’ll keep skin supple and soft, while your serum is a treatment designed to sink into skin more deeply to address your skin priorities. Just remember that one doesn’t replace the other—you’ll still need the emollient properties of your face oil to seal in the benefits of the serum.
How long does it take to see results?
While you’ll likely experience instant gratification with your moisturizer (you put it on and skin feels…more moisturized), serums require loyalty and patience. You likely won’t notice any significant skin shifts for some time—especially if you’re looking for things like increased collagen or brightening. “Some serums might increase radiance immediately by improving light reflection off skin, but most take several weeks to exert their benefits,” Zeichner says. Spoiler alert: they’re worth the wait.