“The main goal of an essence is to hydrate the skin and to help the other products in your skincare routine better absorb into your skin,” says board-certified dermatologist and founder of Epione Beverly Hills, Simon Ourian, MD, who boasts celeb clients like Kim Kardashian. “An essence includes a lot of great benefits for your skin and acts as a primer for your skincare routine. It makes the active ingredients in your existing skincare steps that much more effective. It provides a ton of moisture deep within the skin, restoring the natural moisture balance.” Since an essence has a more liquidy texture than a serum (but is thicker than water) and is usually clear, it’s hard to imagine they actually do anything; but they improve the efficacy of products you layer on top of them. We compiled what you need to know about essences, including the answer to, “Do I really need one?”

What does an essence do?

“Essences originated in Korea and are considered the powerhouse step in the skincare routine,” says Vanessa Lee, RN, renowned aesthetic nurse, injection educator, and founder of The Things We Do in Los Angeles. “Essences usually carry a higher dose of active ingredients and are meant as a ’treatment’ for the skin.” “An essence is used to support the benefits of all the other products in your routine,” Dr. Ourian adds. “The active ingredients within an essence will penetrate even deeper into your skin, working to better enhance your other skincare products and making your entire skincare routine more effective. It’s a vital part of maintaining your skin’s health.”

How should I incorporate essences in my skincare routine?

Cleanse your skin first—double cleanse if you’re sticking to a traditional Korean routine—and then immediately apply the essence. If using an astringent or pH-balancing toner in your routine, apply it between your cleanser and essence; but typically, you want essence to be the first layer that goes onto dry skin. After that, apply the rest of your routine as normal: lightest to heaviest, starting with serums and working toward moisturizer.

Are essences meant to layer on top of each other the way serums do?

Essentially, no. “Essences are lighter in weight and less concentrated than a serum, so you only need to use one essence in your skincare routine at a time,” says Dr. Ourian. Celebrity esthetician Renee Rouleau adds, “The skin can only absorb so much, so you don’t want to layer too much on the skin as you’ll waste product.”

What’s the difference between traditional toners (like astringent formulas) and essences?

“Essences can easily be confused with toners because they have a consistency that can range from watery to a light serum, but they should be respected in their own category,” Lee explains. “Toners are meant to help balance the skin pH and prep the skin for more efficacious ingredient delivery in the products to follow. Serums generally have a higher molecular weight than essences and carry more emollient and humectant properties. Because they’re specifically made for the delivery of active ingredients in a lightweight formula to be absorbed well by the skin, it makes it one of the most important steps of the Korean skincare routine.” Dr. Ourian also notes there’s a difference in the way each product is applied. “You apply an essence with your hands whereas with a toner, you typically use a cotton pad of some sort to wipe across your face,” he says. “Using a cotton pad with an essence essentially leaves a lot of product on the cotton pad, not on your skin.”

Is an essence really necessary in my skincare routine?

“Using a hydrating, serum-infused toner [or essence] a few times a day will go a long way,” says Rouleau. “They pamper and soothe thirsty skin cells by delivering moisture deep into the skin. Doing this a few times a day will remove dirt and oil buildup while simultaneously soothing the skin.” Dr. Ourian and Lee agree that essences are a necessity in your a.m. and p.m. skincare routines. But Lee cautions to examine the essence’s ingredients and purpose, as some are formulated with brightening ingredients that can make your skin more photosensitive (aggravating your skin’s sensitivity to sunlight). If we’ve convinced you that essences are a must in your routine, check out these recommendations from our experts. It combines hero ingredients like lotus extract, niacinamide, yeast ferment, and bamboo extract to deliver deep hydration, irritation relief, and brightening with continued use. It’s ultra-gentle, and just a couple drops go a long way, so one bottle lasts a while. To buy: $39, ulta.com. To buy: $225; violetgrey.com. “Not only does it help with skin brightening,” Lee explained, “my breakouts automatically decrease when I regularly use this specific one because of the high quality fermented ingredients and red algae.” This TIMY product contains polyglutamic acid, claimed to hold four times as much moisture as hyaluronic acid (a known hydration magnet in skincare). Plus, black chokeberry (which is rich in antioxidants) helps protect skin from pollution and other environmental stressors. To buy: $50; sokoglam.com. To buy: $105; sephora.com. To buy: $52; sephora.com.