Skin Care 101: What Ingredients To Layer (& What Not To)

Skin care is a science (which, TBH, was not our best subject in school). The ingredients in our products might as well be in another language, and half the time we can't even pronounce them. We know the necessary essentials — cleanser, serum, eye cream, SPF, and moisturizer — and that it helps to know one's skin type. But short of donning a white lab coat and goggles, how do we create the perfect concoction of ingredients and formulas to get the desired result?

Consider this an intro course to skin-care cocktailing. With the help of dermatologist Joshua Zeichner and aesthetician Christine Chin, we identified which ingredients are a match made in heaven and which can lead to nasty side effects when combined. So if we keep an eye on labels, and/or reach for made-to-mix products like the new Clarins Boosters to get the best results, we'll be sure to ace this skin-care test.
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Illustrated by Alex Marino
Do: Retinol + Hyaluronic Acid Or Glycerin
Retinol is a powerhouse ingredient for smoothing fine lines, but it can also irritate and dry out the skin, says Chin. Follow any retinol products with a moisturizer that contains super-hydrating glycerin or hyaluronic acid to counter harsh drying effects.
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Illustrated by Alex Marino
Do: Salicylic Acid + Soy Or Licorice
This combo is perfect for curing acne — both old and new. Soy and licorice heal and fade acne scars, while salicylic acid prevents new ones from popping up. Add these to your routine by washing with a salicylic acid cleanser, then applying a soy- or licorice-enriched moisturizer or night cream. So long, pesky pimples.
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Illustrated by Alex Marino
Do: Benzoyl Peroxide + Salicylic & Glycolic Acids
For more frequent acne, use salicylic acid and benzoyl peroxide in conjunction with each other for a one-two punch. First, cleanse with glycolic- or salicylic acid-based face wash to control excess oil production. Then, use a benzoyl peroxide-based spot treatment to kill any lingering bacteria and shrink existing spots.
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Illustrated by Alex Marino
Do: Vitamin C + Peptides
Think of peptides as batteries that energize and super-charge certain ingredients to do a more effective job. Infuse your night cream or moisturizer with an extra dose of peptides by adding a couple drops of the Clarins Booster Energy. Then, follow with a vitamin C-infused serum. The vitamin C will work to banish dullness and increase skin-cell turnover, while the peptides will make skin more resilient.
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Illustrated by Alex Marino
Don't: Citric Acid + Literally Anything
Citric acids, not to be confused with vitamin C, can be ace when it comes to exfoliating. But layer them on top of anything else, and the higher-than-average pH levels can cause serious irritation. The lesson here: If you see "citric" on the label, be prepared to use this product and this product only.
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Illustrated by Alex Marino
Don't: Retinol + Acne Treatments
We've already told you that retinol can be a fickle friend, but it's even more so when used with acne treatments. Combining retinol with salicylic acid can cause extreme dryness and redness. And mixing it with benzoyl peroxide actually deactivates the two ingredients, so you get neither the anti-aging results or the acne treatment you desire. Instead, keep things separate by applying acne formulas in the morning and retinol only at night.
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Illustrated by Alex Marino
Don't: Vitamin C + Alpha Hydroxy Acids (AHAs)
AHAs can alter the pH level of vitamin C, destabilizing it and rendering this powerful antioxidant (and consequently the beauty product you shelled out some dough for) ineffective. And if you suffer from rosacea or extreme dryness, the excess acidity can exacerbate your condition, says Chin.
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Illustrated by Alex Marino
Don't: Salicylic Acid + AHAs
Two isn't always better than one when it comes to acids. Think of salicylic acid and AHAs as two major heavyweight champs. Each one tries to make the biggest difference on your skin, but their combined strength ends up making things worse. Chin says to steer clear of the combo, or risk red, sore, and itchy skin. You can, however, use salicylic acid with glycolic and lactic acid for enhanced exfoliation, says Dr. Zeichner.

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